Compositions and methods for enhanced gene expression in cone cells

ABSTRACT

The present disclosure provides polynucleotide cassettes, expression vectors and methods for the expression of a gene in cone cells.

CROSS REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119 (e), this application claims priority to the filing dates of U.S. Provisional Patent Application Ser. No. 61/954,330 filed Mar. 17, 2014; and U.S. Provisional Patent Application Ser. No. 62/127,185 filed Mar. 2, 2015, the full disclosures of which are herein incorporated by reference.

STATEMENT REGARDING SEQUENCE LISTING

The Sequence Listing associated with this application is provided in text format in lieu of a paper copy, and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is AVBI_005_02US_ST25.txt. The text file is 308 KB, was created on Mar. 17, 2015, and is being submitted electronically via EFS-Web.

FIELD OF THE INVENTION

This invention pertains to gene therapy of retinal disorders.

BACKGROUND OF THE INVENTION

Vision disorders of the eye often relate to known primary defects in cone cells. These include macular dystrophies such as Stargardt's macular dystrophy, cone dystrophy, cone-rod dystrophy, Spinocerebellar ataxia type 7, and Bardet-Biedl syndrome-1, as well as color vision disorders, including achromotopsia, blue cone monochromacy, and protan, deutan, and tritan defects.

In addition to those disorders where the known cause is intrinsic to cone photoreceptors, there are vision disorders of the central macula (within primates) that may be treated by targeting cone cells. These include age-related macular degeneration, macular telangiectasia, retinitis pigmentosa, diabetic retinopathy, retinal vein occlusions, glaucoma, Sorsby's fundus dystrophy, adult vitelliform macular dystrophy, Best's disease, and X-linked retinoschisis.

A promising approach to treating and preventing ophthalmic disease that addresses the limitations of existing treatment is delivery of therapeutic agents to the eye with a gene therapy vector such as an adeno-associated virus (AAV). AAV is a 4.7 kb, single stranded DNA virus. Recombinant vectors based on AAV are associated with excellent clinical safety, since wild-type AAV is nonpathogenic and has no etiologic association with any known diseases. In addition, AAV offers the capability for highly efficient gene delivery and sustained transgene expression in numerous tissues, including eye, muscle, lung, and brain. Furthermore, AAV has shown promise in human clinical trials. One example is Leber's congenital amaurosis in which patients treated with a therapeutic delivered by a single subretinal administration of an rAAV vector have experienced sustained clinical benefit from expression of the therapeutic agent for more than four years from the initial date of treatment.

A number of challenges remain with regard to designing polynucleotide cassettes and expression vectors for use in gene therapy to treat eye disease generally and cone cells specifically. One significant challenge is obtaining sufficient expression of the transgene in target cells, especially in cone cells of the retina. A longstanding unmet need in the art has been sufficiently robust expression of transgenes following gene transfer. In some cases, more efficient expression is required for the efficacy of certain vectors, for example plasmid DNA vectors. In other cases, more efficient gene expression cassettes are desirable to allow for a lower therapeutic dose that has a more favorable safety profile or a less invasive route of administration (e.g., intravitreal vs. subretinal). In some settings, efficient expression has been achieved using a strong, ubiquitous promoter, but it is often desirable to have high transgene expression using a nucleic acid expression cassette that is only expressed in target cell types.

Previous efforts to express transgenes in cone cells, for example as disclosed in US patent application US 2012/0172419, showed some promise, but often the expression levels were lower than optimal or not cell specific. Given that a number of vision disorders result from primary defects in cone cells, specific expression of transgenes in cone cells, with high expression levels, would represent a meaningful advance in the art. Therefore, there remains a need for improved methods and optimized nucleic acid cassettes and vectors for expressing genes in cone cells.

SUMMARY OF THE INVENTION

The present disclosure provides polynucleotide cassettes, expression vectors and methods for the expression of a gene in cone cells.

In some aspects of the invention, polynucleotide cassettes are provided for the expression of a transgene in cone cells of a mammalian retina. In some embodiments, the expression of the transgene is enhanced expression. In certain embodiments, the expression of the coding sequence is greater than expression of the transgene operably linked to SEQ ID NO:1. In some embodiments, the expression of the transgene is cone-specific.

In some embodiments, the polynucleotide cassette comprises a promoter region, wherein the promoter region promotes the expression of a gene in retinal cone cells; and a polyadenylation site. In some embodiments, the expression is specifically in cone cells. In some such embodiments, the promoter region comprises a polynucleotide sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:79, SEQ ID NO:80, SEQ ID NO:81. SEQ ID NO:82, and SEQ ID NO:83, or a functional fragment thereof. In some embodiments, the promoter region is less than 492 nucleotides in length. In some embodiments, the promoter region consists essentially of a polynucleotide sequence having a sequence identity of 85% or more to the full length of SEQ ID NO:55 or a functional fragment thereof.

In some embodiments, the polynucleotide cassette comprises a polynucleotide sequence encoding an untranslated region 5′ for a coding sequence, referred to herein as a 5′UTR. In some such embodiments, the 5′UTR comprises a sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:84, SEQ ID NO:85, SEQ ID NO:86, SEQ ID NO:87, SEQ ID NO:88, and SEQ ID NO:89, or a fragment thereof. In some embodiments, some or all of the 5′UTR sequence is comprised by a promoter region as disclosed in, for example, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO:55, or SEQ ID NO:79. In some embodiments, the 5′UTR sequence is heterologous to the promoter sequence. In some embodiments, the 5′UTR consists essentially of a sequence having a sequence identity of 85% or more to the full length of SEQ ID NO:85 or SEQ ID NO:86, or a fragment thereof. In some embodiments, the 5′UTR does not comprise a polynucleotide ATG.

In some embodiments, the polynucleotide cassette comprises an intron. In some such embodiments, the intron comprises a sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:59, and SEQ ID NO:60. In certain embodiments, the intron is located within the polynucleotide sequence encoding a 5′UTR.

In some embodiments, the polynucleotide cassette comprises a translation initiation sequence. In some such embodiments, the translation initiation sequence comprises a polynucleotide sequence consisting essentially of SEQ ID NO:72 or SEQ ID NO:73.

In some embodiments, the polynucleotide cassette comprises an enhancer sequence. In some such embodiments, the enhancer sequence comprises a polynucleotide sequence having a sequence identity of 85% or more to SEQ ID NO:52 or a functional fragment thereof. In certain embodiments, the enhancer sequence consists essentially of a sequence having a sequence identity of 85% or more to the full length of SEQ ID NO:51.

In some embodiments, the polynucleotide cassette comprises a coding sequence operably linked to the promoter. In some embodiments, the coding sequence is heterologous to the promoter region and/or the 5′UTR sequence. In some embodiments, the coding sequence encodes a polypeptide having a sequence identity of at least 85%, 90%, or 95% to SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13, SEQ ID NO:15, SEQ ID NO:17, SEQ ID NO:19, SEQ ID NO:21, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41, SEQ ID NO:43, SEQ ID NO:45, SEQ ID NO:47, SEQ ID NO:49, and a polymorph of SEQ ID NO:11 selected from the group consisting of: (i) Thr65Ile (ii) Ile111Val (iii) Ser116Tyr (iv) Leu153Met (v) Ile171Val (vi) Ala174Val (vii) Ile178Val (viii) Ser180Ala (ix) Ile230Thr (x) Ala233Ser (xi) Val236Met (xii) Ile274Val (xiii) Phe275Leu (xiv) Tyr277Phe (xv) Val279Phe (xvi) Thr285Ala (xvii) Pro298Ala; and (xviii) Tyr309Phe. In some embodiments, the coding sequence has a sequence identity of at least 85%, 90%, or 95% to SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, SEQ ID NO:16, SEQ ID NO:18, SEQ ID NO:20, SEQ ID NO:22, SEQ ID NO:34, SEQ ID NO:36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44, SEQ ID NO:46, SEQ ID NO:48, SEQ ID NO:61, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ ID NO:65, SEQ ID NO:66, SEQ ID NO:67, SEQ ID NO:68, SEQ ID NO:69, SEQ ID NO:70, or SEQ ID NO:71. In some embodiments, the sequence between the transcription initiation site and the end of coding sequence does not contain an open reading frame, other than the transgene open reading frame, that is more than 500 nucleotides in length. In some embodiments, the sequence between the transcription initiation site and the end of coding sequence does not contain an open reading frame, other than the transgene open reading frame, that is more than 273 nucleotides in length. In some embodiments, the sequence between the transcription initiation site and the end of coding sequence does not contain an open reading frame, other than the transgene open reading frame, that is more than 250 nucleotides in length. In some embodiments, at least one open reading frame of the coding sequence has been removed.

In some embodiments, the polynucleotide comprises a promoter region, wherein the promoter region promotes the expression of a gene in retinal cone cells; a 5′ untranslated region; an intron; a translation initiation sequence; a coding sequence operatively linked to the promoter region; and a polyadenlyation site. In some embodiments, the polynucleotide comprises a promoter region, wherein the promoter region promotes the expression of a gene specifically in retinal cone cells; a 5′ untranslated region; an intron; a translation initiation sequence; a coding sequence operatively linked to the promoter region; and a polyadenlyation site.

In some aspects of the invention, gene delivery vectors are provided comprising a polynucleotide cassette of the present invention. In some embodiments, the gene delivery vector is a recombinant adeno-associated virus, wherein the recombinant adeno-associated virus comprises an AAV capsid protein. In some embodiments, the AAV capsid protein is a wild type AAV capsid protein. In other embodiments, the AAV capsid protein is a variant AAV capsid protein. In certain embodiments, the variant AAV capsid protein comprises a peptide insertion in the AAV GH loop selected from the group consisting of LGETTRP (SEQ ID NO:96), NETITRP (SEQ ID NO:97), KAGQANN (SEQ ID NO:98), KDPKTTN (SEQ ID NO:99), KDTDTTR (SEQ ID NO:100), RAGGSVG (SEQ ID NO:101), AVDTTKF (SEQ ID NO:102), and STGKVPN (SEQ ID NO:103).

In some aspects of the invention, pharmaceutical compositions are provided comprising a polynucleotide cassette of the invention and a pharmaceutical excipient. In some embodiments, the pharmaceutical composition comprises a gene delivery vector of the invention and a pharmaceutical excipient.

In some aspects of the invention, methods are provided for expressing a transgene in cone cells. In some embodiments, the method comprises contacting one or more cone cells with an effective amount of a polynucleotide cassette of the invention or a gene delivery vector of the invention, wherein the transgene is expressed at detectable levels in the one or more cone cells. In some embodiments, the method is in vitro. In other embodiments, the method is in vivo. In certain such embodiments, the contacting comprises injection of the polynucleotide cassette or gene delivery vector into the vitreous of a mammal eye. In other such emobidments, the method comprises injection of the polynucleotide cassette or gene delivery vector into the subretinal space of a mammal eye. In some embodiments, the method further comprises detecting the expression of the trangene in cone cells, wherein expression is detected in 80% or more of the cone cells. In some embodiments, the expression is specific for cone cells.

In some aspects of the invention, methods are provided for the treatment or prophylaxis of a cone cell disorder in a mammal in need of treatment or prophylaxis for a cone cell disorder. In some embodiments, the method comprises administering to the eye of the mammal an effective amount of a pharmaceutical composition of the invention, wherein the coding sequence encodes a therapeutic gene product. In some embodiments, the administering comprises injecting the pharmaceutical composition into the vitreous of the mammal eye. In other such embodiments, the method comprises injecting the pharmaceutical composition into the subretinal space of a mammal eye.

In some embodiments, the cone cell disorder is a color vision disorder. In certain embodiments, the color vision disorder is selected from the group consisting of achromotopsia, blue cone monochromacy, a protan defect, a deutan defect, and a tritan defect. In some such embodiments, the method further comprises detecting a change in the disease symptoms, wherein the change comprises an increase in the ability of the mammal to perceive a color. In some embodiments, the cone cell disorder is a macular dystrophy. In certain embodiments, the macular dystrophy is selected from the group consisting of Stargardt's macular dystrophy, cone dystrophy, cone-rod dystrophy, Spinocerebellar ataxia type 7, and Bardet-Biedl syndrome-1. In some embodiments, the cone cell disorder is a vision disorder of the central macula. In certain embodiments, vision disorder of the central macula is selected from the group consisting of age-related macular degeneration, macular telangiectasia, retinitis pigmentosa, diabetic retinopathy, retinal vein occlusions, glaucoma, Sorsby's fundus dystrophy, adult vitelliform macular dystrophy, Best's disease, rod-cone dystrophy, Leber's congenital amaurosis, and X-linked retinoschisis. In some such embodiments, the method further comprises detecting a change in the disease symptoms. In some such embodiments, the change comprises a stabilization in the health of the cone cells and/or a reduction in the rate of visual acuity loss of the mammal. In certain such embodiments, the change comprises an improvement in the health of the cone cells and/or an improvement in the visual acuity of the mammal.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

FIG. 1A depicts the schematic overview of polynucleotide cassettes for enhanced expression of a transgene in cone cells.

FIG. 1B depicts a schematic overview of viral vectors comprising polynucleotide cassettes for enhanced expression of a transgene in cone cells.

FIG. 2 depicts an example intron containing canonical features, including consensus sequences for the splice donor (A/C) A G G T Pu A G U; branch site C T Pu A Py; Py-rich region; and acceptor N C A G G.

FIG. 3A depicts an example 5′UTR mRNA structure (SEQ ID NO:56), the 5′UTR mRNA structure from pR2.1 (Mancuso et al.). This 5′ UTR has two upstream AUGs and open reading frames (ORF), a high level of base pairing and hairpin structure, and a shorter Kozak sequence.

FIG. 3B depicts an example 5′UTR mRNA and structure (SEQ ID NO:57) from an optimized cassette of the present disclosure. The 5′ UTR comprises no upstream AUG and no ORFs. In addition, as compared to the 5′ UTR of FIG. 3A, the 5′ UTR of FIG. 3B is shorter, with less base pairing; and the Kozak sequence is longer.

FIG. 4A depicts a polynucleotide cassette before codon optimization. Open reading frames (ORFs) greater than 250 nucleotides in length are shown in gray below the sequence.

FIG. 4B depicts a polynucleotide cassette after codon optimization, but before removal of non-transgene ORFs. ORFs greater than 250 nucleotides are shown in gray below sequence diagram. Note the introduction of a new ORF in reverse orientation beginning from SV40 polyA and extending 1,365 bases.

FIG. 4C depicts a polynucleotide cassette after codon optimization and removal of ORFs. ORFs greater than 250 nucleotides are shown in gray below the sequence diagram. Note that the sequence has been optimized so that newly introduced ORFs are shortened or removed.

FIG. 5 illustrates how intravitreally-delivered AAV2 variant AAV2-7m8 transduces retinal cells in the fovea centralis and parafovea of primates more efficiently than intravitreally-delivered AAV2.5×10¹¹ vector genomes of AAV2.CMV.GFP (upper left); AAV-2.5T.CMV.GFP (upper right) (Excoffon K. J., et al. 2009. Proc. Natl. Acad. Sci. U.S.A. 106:3865-3870); (lower left) AAV2-7.8.CMV.GFP (Dalkara D, et al. Sci Transl Med. 2013 Jun. 12; 5(189):189ra76); or AAV-ShH10.CMV.GFP (lower right) (Klimczak R R et al. PLoS One. 2009 Oct. 14; 4(10):e7467) was injected into the vitreous of an African green monkey in a volume of 50 uL, and GFP expression was observed 8 weeks later by OCT fluorescence imaging in vivo.

FIG. 6 illustrates how robustly the pMNTC regulatory cassette promotes gene expression in foveal cones of primates. (a-b) AAV2-7m8.MNTC.GFP was injected into the central vitreous of a baboon and expression was observed (a) 5 weeks and (b) 8 weeks later by fundus fluorescence. (c and d) Natural GFP fluorescence within a 15 micron section of the fovea at approximately 6 months after injection with AAV2-7m8.MNTC.GFP at low magnification (c) and high magnification (d).

FIG. 7 illustrates robust and cone-specific gene expression in the cones of a mouse retina following intravitreal injection of AAV-delivery MNTC.GFP. (a-b) Examples of GFP fluorescence 11 weeks after mice received intravitreal injections of 5.04×10¹⁰ vector genomes via intravitreal injection. (c-e) retinas were harvested for histology 14 weeks after injection and cone outersegments were labeled with an antibody to L/M opsin (red). In (c) the red channel is turned off so only the native GFP is visible, (d) is the same image with the red channel on to allow visualization of cone outersegments. Comparison of (c) and (d) shows that most if not all cones were transduced by the virus. (e) Image from the same retina as in c and d from different angle showing profiles of cone photoreceptors.

FIG. 8 illustrates gene expression directed by the pMNTC regulatory cassette in the cones of the Mongolian gerbil retina. 1×10¹⁰-2×10¹⁰ vector genomes of virus carrying GFP under the control of the CMV, pR2.1, or MNTC promoter were injected in a volume of 5 uL into the vitreous of a Mongolian gerbil, and GFP expression visualized at the designated time points by fundus fluorescence imaging. (a) Expression of GFP directed by AAV2-7m8.CMV.GFP and AAV2-7m8.MNTC.GFP, visualized 4 weeks after intravitreal administration. Gerbils 12-10, 12-11, and 12-12 were injected with AAV2-7m8.CMV.GFP, while gerbils 12-13, 12-14, and 12-15 were injected with AAV2-7m8.MNTC.GFP. OD, oculus dexter (right eye). OS, oculus sinister (left eye). (b) Expression of GFP directed by AAV2-7m8.pR2.1.GFP and AAV2-7m8.MNTC.GFP, 4 and 8 weeks later as detected by fundus fluorescence imaging.

FIGS. 9A-9D demonstrate that the pMNTC regulatory cassette provides for more robust gene expression in foveal cones of primates than the cone promoter pR2.1. 5×10¹¹ vector genomes of AAV2-7m8.MNTC.GFP or AAV2-7m8.pR2.1.GFP were injected in a volume of 50 uL into the vitreous of African Green Monkeys as indicated (AAV2-7m8.MNTC.GFP into animals 271 and 472; AAV2-7m8.pR2.1.GFP into animals 500 and 509). Retinas were visualized in vivo at (a) 2 weeks, (b) 4 weeks, (c) 8 weeks, and (d) 12 weeks for GFP using a fundus fluorescence camera (a, b, c, d) or autofluorescence on Heidelberg Spectralis OCT (a, b; data not shown for weeks 8 and 12). OD, oculus dexter (right eye). OS, oculus sinister (left eye).

FIGS. 10A-10D demonstrate the contribution of each of the optimized pMNTC elements to the more robust expression observed. (a) The pMNTC and pR2.1 expression cassettes. (b) The experimental expression cassettes, in which each element in pMNTC is replaced one-by-one by the corresponding element in pR2.1. (c,d) Expression of the luciferase transgene in the retinas of gerbils intravitreally injected with each of the test articles (n=6-8 eyes per construct) as detected (c) 4 weeks and (d) 8 weeks after injection by IVIS imaging. “7m8.CMV” served as the positive control.

DEFINITIONS

A “vector” as used herein refers to a macromolecule or association of macromolecules that comprises or associates with a polynucleotide and which can be used to mediate delivery of the polynucleotide to a cell. Illustrative vectors include, for example, plasmids, viral vectors, liposomes, and other gene delivery vehicles.

The term “AAV” is an abbreviation for adeno-associated virus, and may be used to refer to the virus itself or derivatives thereof. The term covers all subtypes and both naturally occurring and recombinant forms, except where required otherwise. The term “AAV” includes AAV type 1 (AAV-1), AAV type 2 (AAV-2), AAV type 3 (AAV-3), AAV type 4 (AAV-4), AAV type 5 (AAV-5), AAV type 6 (AAV-6), AAV type 7 (AAV-7), AAV type 8 (AAV-8), avian AAV, bovine AAV, canine AAV, equine AAV, primate AAV, non-primate AAV, and ovine AAV. “Primate AAV” refers to AAV that infect primates, “non-primate AAV” refers to AAV that infect non-primate mammals, “bovine AAV” refers to AAV that infect bovine mammals, etc.

An “AAV virus” or “AAV viral particle” or “rAAV vector particle” refers to a viral particle composed of at least one AAV capsid protein (typically by all of the capsid proteins of a wild-type AAV) and an encapsidated polynucleotide rAAV vector. If the particle comprises a heterologous polynucleotide (i.e. a polynucleotide other than a wild-type AAV genome such as a transgene to be delivered to a mammalian cell), it is typically referred to as a “rAAV vector particle” or simply a “rAAV vector”. Thus, production of rAAV particle necessarily includes production of rAAV vector, as such a vector is contained within a rAAV particle.

The term “replication defective” as used herein relative to an AAV viral vector of the invention means the AAV vector cannot independently replicate and package its genome. For example, when a cell of a subject is infected with rAAV virions, the heterologous gene is expressed in the infected cells, however, due to the fact that the infected cells lack AAV rep and cap genes and accessory function genes, the rAAV is not able to replicate further.

An “AAV variant” or “AAV mutant” as used herein refers to a viral particle composed of: a) a variant AAV capsid protein, where the variant AAV capsid protein comprises at least one amino acid difference (e.g., amino acid substitution, amino acid insertion, amino acid deletion) relative to a corresponding parental AAV capsid protein, and where the variant capsid protein confers increased infectivity of a retinal cell compared to the infectivity of the retinal cell by an AAV virion comprising the corresponding parental AAV capsid protein, where the AAV capsid protein does not comprise an amino acid sequence present in a naturally occurring AAV capsid protein; and b) a heterologous nucleic acid comprising a nucleotide sequence encoding a heterologous gene product.

The abbreviation “rAAV” refers to recombinant adeno-associated virus, also referred to as a recombinant AAV vector (or “rAAV vector”). A “rAAV vector” as used herein refers to an AAV vector comprising a polynucleotide sequence not of AAV origin (i.e., a polynucleotide heterologous to AAV), typically a sequence of interest for the genetic transformation of a cell. In general, the heterologous polynucleotide is flanked by at least one, and generally by two AAV inverted terminal repeat sequences (ITRs). The term rAAV vector encompasses both rAAV vector particles and rAAV vector plasmids.

As used herein, the term “gene” or “coding sequence” refers to a nucleotide sequence in vitro or in vivo that encodes a gene product. In some instances, the gene consists or consists essentially of coding sequence, that is, sequence that encodes the gene product. In other instances, the gene comprises additional, non-coding, sequence. For example, the gene may or may not include regions preceding and following the coding region, e.g. 5′ untranslated (5′ UTR) or “leader” sequences and 3′ UTR or “trailer” sequences, as well as intervening sequences (introns) between individual coding segments (exons).

As used herein, a “therapeutic gene” refers to a gene that, when expressed, confers a beneficial effect on the cell or tissue in which it is present, or on a mammal in which the gene is expressed. Examples of beneficial effects include amelioration of a sign or symptom of a condition or disease, prevention or inhibition of a condition or disease, or conferral of a desired characteristic. Therapeutic genes include genes that correct a genetic deficiency in a cell or mammal.

As used herein, a transgene is a gene that is delivered to a cell by a vector.

As used herein, the term “gene product” refers to the desired expression product of a polynucleotide sequence such as a polypeptide, peptide, protein or interfering RNA including short interfering RNA (siRNA), miRNA or small hairpin RNA (shRNA).

As used herein, the terms “polypeptide,” “peptide,” and “protein” refer to polymers of amino acids of any length. The terms also encompass an amino acid polymer that has been modified; for example, disulfide bond formation, glycosylation, lipidation, phosphorylation, or conjugation with a labeling component.

By “comprising” it is meant that the recited elements are required in, for example, the composition, method, kit, etc., but other elements may be included to form the, for example, composition, method, kit etc. within the scope of the claim. For example, an expression cassette “comprising” a gene encoding a therapeutic polypeptide operably linked to a promoter is an expression cassette that may include other elements in addition to the gene and promoter, e.g. poly-adenylation sequence, enhancer elements, other genes, linker domains, etc.

By “consisting essentially of”, it is meant a limitation of the scope of the, for example, composition, method, kit, etc., described to the specified materials or steps that do not materially affect the basic and novel characteristic(s) of the, for example, composition, method, kit, etc. For example, an expression cassette “consisting essentially of” a gene encoding a therapeutic polypeptide operably linked to a promoter and a polyadenylation sequence may include additional sequences, e.g. linker sequences, so long as they do not materially affect the transcription or translation of the gene. As another example, a variant, or mutant, polypeptide fragment “consisting essentially of” a recited sequence has the amino acid sequence of the recited sequence plus or minus about 10 amino acid residues at the boundaries of the sequence based upon the full length naïve polypeptide from which it was derived, e.g. 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 residue less than the recited bounding amino acid residue, or 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 residues more than the recited bounding amino acid residue.

By “consisting of”, it is meant the exclusion from the composition, method, or kit of any element, step, or ingredient not specified in the claim. For example, an expression cassette “consisting of” a gene encoding a therapeutic polypeptide operably linked to a promoter, and a polyadenylation sequence consists only of the promoter, polynucleotide sequence encoding the therapeutic polypeptide, and polyadenlyation sequence. As another example, a polypeptide “consisting of” a recited sequence contains only the recited sequence.

As used herein, the terms “sequence identity,” e.g. “% sequence identity,” refers to the degree of identity between two or more polynucleotides when aligned using a nucleotide sequence alignment program; or between two or more polypeptide sequences when aligned using an amino acid sequence alignment program. Similarly, the term “identical” or percent “identity” when used herein in the context of two or more nucleotide or amino acid sequences refers to two sequences that are the same or have a specified percentage of amino acid residues or nucleotides when compared and aligned for maximum correspondence, for example as measured using a sequence comparison algorithm, e.g. the Smith-Waterman algorithm, etc., or by visual inspection. For example, the percent identity between two amino acid sequences may be determined using the Needleman and Wunsch, (1970, J. Mol. Biol. 48: 444-453) algorithm which has been incorporated into the GAP program in the GCG software package, using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6. As another example, the percent identity between two nucleotide sequences may be determined using the GAP program in the GCG software package, using a NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1, 2, 3, 4, 5, or 6. A particularly preferred set of parameters (and the one that should be used unless otherwise specified) are a Blossum 62 scoring matrix with a gap penalty of 12, a gap extend penalty of 4, and a frameshift gap penalty of 5. The percent identity between two amino acid or nucleotide sequences can also be determined using the algorithm of E. Meyers and W. Miller (1989, Cabios, 4: 11-17) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. The nucleic acid and protein sequences described herein can be used as a “query sequence” to perform a search against public databases to, for example, identify other family members or related sequences. Such searches can be performed using the NBLAST and XBLAST programs (version 2.0) of Altschul, et al., (1990, J. Mol. Biol, 215: 403-10). BLAST nucleotide searches can be performed with the NBLAST program, score=100, wordlength=12 to obtain nucleotide sequences homologous to nucleic acid molecules of the invention. BLAST protein searches can be performed with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to protein molecules of the invention. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al., (1997, Nucleic Acids Res, 25: 3389-3402). When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used.

The term “% homology” is used interchangeably herein with the term “% identity” herein and refers to the level of nucleic acid or amino acid sequence identity between two or more aligned sequences, when aligned using a sequence alignment program. For example, as used herein, 80% homology means the same thing as 80% sequence identity determined by a defined algorithm, and accordingly a homologue of a given sequence has greater than 80% sequence identity over a length of the given sequence.

As used herein, the terms “complement” and “complementary” refer to two antiparallel nucleotide sequences capable of pairing with one another upon formation of hydrogen bonds between the complementary base residues in the antiparallel nucleotide sequences. For example, an shRNA might be complementary, i.e. 100% complementary, or substantially complementary, e.g. 80% complementary, 85% complementary, 90% complementary, 95% complementary, 98% complementary, or more to a target sequence. The term “expression” as used herein encompasses the transcription and/or translation of an endogenous gene, a transgene or a coding sequence in a cell.

An “expression vector” as used herein encompasses a vector, e.g. plasmid, minicircle, viral vector, liposome, and the like as discussed above or as known in the art, comprising a polynucleotide which encodes a gene product of interest, and is used for effecting the expression of a gene product in an intended target cell. An expression vector also comprises control elements operatively linked to the encoding region to facilitate expression of the gene product in the target. The combination of control elements, e.g. promoters, enhancers, UTRs, miRNA targeting sequences, etc., and a gene or genes to which they are operably linked for expression is sometimes referred to as an “expression cassette.” Many such control elements are known and available in the art or can be readily constructed from components that are available in the art.

A “promoter” as used herein encompasses a DNA sequence that directs the binding of RNA polymerase and thereby promotes RNA synthesis, i.e., a minimal sequence sufficient to direct transcription. Promoters and corresponding protein or polypeptide expression may be ubiquitous, meaning strongly active in a wide range of cells, tissues and species or cell-type specific, tissue-specific, or species specific. Promoters may “constitutive,” meaning continually active, or “inducible,” meaning the promoter can be activated or deactivated by the presence or absence of biotic or abiotic factors. Also included in the nucleic acid constructs or vectors of the invention are enhancer sequences that may or may not be contiguous with the promoter sequence. Enhancer sequences influence promoter-dependent gene expression and may be located in the 5′ or 3′ regions of the native gene.

An “enhancer” as used herein encompasses a cis-acting element that stimulates or inhibits transcription of adjacent genes. An enhancer that inhibits transcription also is termed a “silencer”. Enhancers can function (i.e., can be associated with a coding sequence) in either orientation, over distances of up to several kilobase pairs (kb) from the coding sequence and from a position downstream of a transcribed region.

A “termination signal sequence” as used herein encompasses any genetic element that causes RNA polymerase to terminate transcription, such as for example a polyadenylation signal sequence.

A “polyadenylation signal sequence” as used herein encompasses a recognition region necessary for endonuclease cleavage of an RNA transcript that is followed by the polyadenylation consensus sequence AATAAA. A polyadenylation signal sequence provides a “polyA site”, i.e. a site on a RNA transcript to which adenine residues will be added by post-transcriptional polyadenylation.

As used herein, the terms “operatively linked” or “operably linked” refers to a juxtaposition of genetic elements, e.g. promoter, enhancer, termination signal sequence, polyadenylation sequence, etc., wherein the elements are in a relationship permitting them to operate in the expected manner. For instance, a promoter is operatively linked to a coding region if the promoter helps initiate transcription of the coding sequence. There may be intervening residues between the promoter and coding region so long as this functional relationship is maintained. As used herein, the term “heterologous” means derived from a genotypically distinct entity from that of the rest of the entity to which it is being compared. For example, a polynucleotide introduced by genetic engineering techniques into a plasmid or vector derived from a different species is a heterologous polynucleotide. As another example, a promoter removed from its native coding sequence and operatively linked to a coding sequence with which it is not naturally found linked is a heterologous promoter. Thus, for example, an rAAV that includes a heterologous nucleic acid encoding a heterologous gene product is an rAAV that includes a nucleic acid not normally included in a naturally-occurring, wild-type AAV, and the encoded heterologous gene product is a gene product not normally encoded by a naturally-occurring, wild-type AAV.

The term “endogenous” as used herein with reference to a nucleotide molecule or gene product refers to a nucleic acid sequence, e.g. gene or genetic element, or gene product, e.g. RNA, protein, that is naturally occurring in or associated with a host virus or cell.

The term “native” as used herein refers to a nucleotide sequence, e.g. gene, or gene product, e.g. RNA, protein, that is present in a wildtype virus or cell. The term “variant” as used herein refers to a mutant of a reference polynucleotide or polypeptide sequence, for example a native polynucleotide or polypeptide sequence, i.e. having less than 100% sequence identity with the reference polynucleotide or polypeptide sequence. Put another way, a variant comprises at least one amino acid difference (e.g., amino acid substitution, amino acid insertion, amino acid deletion) relative to a reference polynucleotide sequence, e.g. a native polynucleotide or polypeptide sequence. For example, a variant may be a polynucleotide having a sequence identity of 70% or more with a full length native polynucleotide sequence, e.g. an identity of 75% or 80% or more, such as 85%, 90%, or 95% or more, for example, 98% or 99% identity with the full length native polynucleotide sequence. As another example, a variant may be a polypeptide having a sequence identity of 70% or more with a full length native polypeptide sequence, e.g. an identity of 75% or 80% or more, such as 85%, 90%, or 95% or more, for example, 98% or 99% identity with the full length native polypeptide sequence. Variants may also include variant fragments of a reference, e.g. native, sequence sharing a sequence identity of 70% or more with a fragment of the reference, e.g. native, sequence, e.g. an identity of 75% or 80% or more, such as 85%, 90%, or 95% or more, for example, 98% or 99% identity with the native sequence.

As used herein, the terms “biological activity” and “biologically active” refer to the activity attributed to a particular biological element in a cell. For example, the “biological activity” of an “immunoglobulin”, “antibody” or fragment or variant thereof refers to the ability to bind an antigenic determinant and thereby facilitate immunological function. As another example, the biological activity of a polypeptide or functional fragment or variant thereof refers to the abilty of the polypeptide or functional fragment or variant thereof to carry out its native functions of, e.g., binding, enzymatic activity, etc. As a third example, the biological activity of a gene regulatory element, e.g. promoter, enhancer, kozak sequence, and the like, refers to the ability of the regulatory element or functional fragment or variant thereof to regulate, i.e. promote, enhance, or activate the translation of, respectively, the expression of the gene to which it is operably linked.

The terms “administering” or “introducing”, as used herein refer to delivery of a vector for recombinant protein expression to a cell, to cells and/or organs of a subject, or to a subject. Such administering or introducing may take place in vivo, in vitro or ex vivo. A vector for expression of a gene product may be introduced into a cell by transfection, which typically means insertion of heterologous DNA into a cell by physical means (e.g., calcium phosphate transfection, electroporation, microinjection or lipofection); infection, which typically refers to introduction by way of an infectious agent, i.e. a virus; or transduction, which typically means stable infection of a cell with a virus or the transfer of genetic material from one microorganism to another by way of a viral agent (e.g., a bacteriophage).

“Transformation” is typically used to refer to bacteria comprising heterologous DNA or cells which express an oncogene and have therefore been converted into a continuous growth mode such as tumor cells. A vector used to “transform” a cell may be a plasmid, virus or other vehicle.

Typically, a cell is referred to as “transduced”, “infected”; “transfected” or “transformed” dependent on the means used for administration, introduction or insertion of heterologous DNA (i.e., the vector) into the cell. The terms “transduced”, “transfected” and “transformed” may be used interchangeably herein regardless of the method of introduction of heterologous DNA.

The term “host cell”, as used herein refers to a cell which has been transduced, infected, transfected or transformed with a vector. The vector may be a plasmid, a viral particle, a phage, etc. The culture conditions, such as temperature, pH and the like, are those previously used with the host cell selected for expression, and will be apparent to those skilled in the art. It will be appreciated that the term “host cell” refers to the original transduced, infected, transfected or transformed cell and progeny thereof.

The terms “treatment”, “treating” and the like are used herein to generally mean obtaining a desired pharmacologic and/or physiologic effect. The effect may be prophylactic in terms of completely or partially preventing a disease or symptom thereof, e.g. reducing the likelihood that the disease or symptom thereof occurs in the subject, and/or may be therapeutic in terms of a partial or complete cure for a disease and/or adverse effect attributable to the disease. “Treatment” as used herein covers any treatment of a disease in a mammal, and includes: (a) preventing the disease from occurring in a subject which may be predisposed to the disease but has not yet been diagnosed as having it; (b) inhibiting the disease, i.e., arresting its development; or (c) relieving the disease, i.e., causing regression of the disease. The therapeutic agent may be administered before, during or after the onset of disease or injury. The treatment of ongoing disease, where the treatment stabilizes or reduces the undesirable clinical symptoms of the patient, is of particular interest. Such treatment is desirably performed prior to complete loss of function in the affected tissues. The subject therapy will desirably be administered during the symptomatic stage of the disease, and in some cases after the symptomatic stage of the disease.

The terms “individual,” “host,” “subject,” and “patient” are used interchangeably herein, and refer to a mammal, including, but not limited to, human and non-human primates, including simians and humans; mammalian sport animals (e.g., horses); mammalian farm animals (e.g., sheep, goats, etc.); mammalian pets (dogs, cats, etc.); and rodents (e.g., mice, rats, etc.).

The various compositions and methods of the invention are described below. Although particular compositions and methods are exemplified herein, it is understood that any of a number of alternative compositions and methods are applicable and suitable for use in practicing the invention. It will also be understood that an evaluation of the expression constructs and methods of the invention may be carried out using procedures standard in the art.

The practice of the present invention will employ, unless otherwise indicated, conventional techniques of cell biology, molecular biology (including recombinant techniques), microbiology, biochemistry and immunology, which are within the scope of those of skill in the art. Such techniques are explained fully in the literature, such as, “Molecular Cloning: A Laboratory Manual”, second edition (Sambrook et al., 1989); “Oligonucleotide Synthesis” (M. J. Gait, ed., 1984); “Animal Cell Culture” (R. I. Freshney, ed., 1987); “Methods in Enzymology” (Academic Press, Inc.); “Handbook of Experimental Immunology” (D. M. Weir & C. C. Blackwell, eds.); “Gene Transfer Vectors for Mammalian Cells” (J. M. Miller & M. P. Calos, eds., 1987); “Current Protocols in Molecular Biology” (F. M. Ausubel et al., eds., 1987); “PCR: The Polymerase Chain Reaction”, (Mullis et al., eds., 1994); and “Current Protocols in Immunology” (J. E. Coligan et al., eds., 1991), each of which is expressly incorporated by reference herein.

Several aspects of the invention are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the invention. One having ordinary skill in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. The present invention is not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and/or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.

The term “about” or “approximately” means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, “about” can mean a range of up to 20%, preferably up to 10%, more preferably up to 5%, and more preferably still up to 1% of a given value. Alternatively, particularly with respect to biological systems or processes, the term can mean within an order of magnitude, preferably within 5-fold, and more preferably within 2-fold, of a value. Where particular values are described in the application and claims, unless otherwise stated the term “about” meaning within an acceptable error range for the particular value should be assumed.

All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. It is understood that the present disclosure supersedes any disclosure of an incorporated publication to the extent there is a contradiction.

It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely”, “only” and the like in connection with the recitation of claim elements, or the use of a “negative” limitation.

The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing-herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.

Unless otherwise indicated, all terms used herein have the same meaning as they would to one skilled in the art and the practice of the present invention will employ, conventional techniques of microbiology and recombinant DNA technology, which are within the knowledge of those of skill of the art.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides polynucleotide cassettes and expression vectors for the expression of a gene in cone cells. Also provided are methods for the use of these compositions in promoting the expression of a gene in cone cells, for example, in an individual, e.g. for the treatment or prophylaxis of a cone cell disorder. These and other objects, advantages, and features of the invention will become apparent to those persons skilled in the art upon reading the details of the compositions and methods as more fully described below.

Compositions

In some aspects of the disclosure, compositions are provided for the expression of a transgene in cone cells. By a “cone cell”, also referred to herein as a “cone photoreceptor” or “cone”, it is meant the subtype of photoreceptor cells in the retina of the eye that function best in relatively bright light. Cones are sensitive to specific wavelengths of light and hence support the perception of color. In addition, cones respond faster to stimuli than rod photoreceptors, perceiving finer detail and more rapid changes in images than rods, and hence, support high acuity vision for activities where visual detail is of primary importance such as reading and driving. Cones are readily identifiable in cross-sections of the retina by the cone-like shape of their outer segments. They are also readily identifiable by their location in the retina, the highest density of cones existing at the 1.5 mm depression located in the center of the macula of the retina, called the “fovea centralis” or “foveal pit”.

In some embodiments of the disclosure, the composition that provides for the expression of a transgene in cone cells is a polynucleotide cassette. By a “polynucleotide cassette” it is meant a polynucleotide sequence comprising two or more polynucleotide sequences, e.g. regulatory elements, translation initiation sequences, coding sequences, termination sequences, etc., typically in operably linkage to one another. Likewise, by a “polynucleotide cassette for the expression of a transgene in a cone cell,” it is meant a combination of two or more polynucleotide sequences, e.g. promoter, enhancer, 5′UTR, translation initiation sequence, coding sequence, termination sequences, etc. that promotes the expression of the transgene in a cone cell.

For example, in some embodiments, the polynucleotide cassette comprises:

-   -   (a) a promoter region, wherein the promoter region promotes the         expression of a coding sequence in cone cells; and     -   (b) a coding sequence operatively linked to the promoter region.         As another example, in some embodiments, the polynucleotide         cassette comprises:     -   (a) a promoter region, wherein the promoter region promotes the         expression of a coding sequence in retinal cone cells;     -   (b) a translation initiation sequence; and     -   (c) a coding sequence operatively linked to the promoter region.         As a third example, in some embodiments, the polynucleotide         cassette comprises:     -   (a) a promoter region, wherein the promoter region promotes the         expression of a coding sequence in retinal cone cells;     -   (b) a 5′ untranslated region;     -   (c) a translation initiation sequence; and     -   (d) a coding sequence operatively linked to the promoter region.         As a fourth example, in some embodiments, the polynucleotide         cassette comprises:     -   (a) a promoter region, wherein the promoter region promotes the         expression of a coding sequence in retinal cone cells;     -   (b) a 5′ untranslated region;     -   (c) an intron;     -   (d) a translation initiation sequence; and     -   (e) a coding sequence operatively linked to the promoter region.         As a fifth example, in some embodiments, the polynucleotide         cassette comprises:     -   (a) a promoter region, wherein the promoter region promotes the         expression of a coding sequence in retinal cone cells;     -   (b) a 5′ untranslated region;     -   (c) an intron;     -   (d) a translation initiation sequence; and     -   (e) a polyadenylation sequence.

In some embodiments, the polynucleotide cassettes of the present disclosure provide for enhanced expression of a transgene in cone cells. As demonstrated by the working examples of the present disclosure, the present inventors have discovered a number of polynucleotide elements, i.e. improved elements as compared to those known in the art, which individually and synergistically provide for the enhanced expression of transgenes in cone cells. By “enhanced” it is meant that expression of the transgene is increased, augmented, or stronger, in cone cells carrying the polynucleotide cassettes of the present disclosure relative to in cone cells carrying the transgene operably linked to comparable regulatory elements, e.g. as known in the art. Put another way, expression of the transgene is increased, augmented, or stronger, from the polynucleotide cassettes of the present disclosure relative to expression from a polynucleotide cassette not comprising the one or more optimized elements of the present disclosure, i.e. a reference control. For example, expression of the transgene is enhanced, or augmented, or stronger, in cone cells comprising a polynucleotide cassette comprising a promoter disclosed herein than in cone cells that carry the transgene operably linked to a different promoter, e.g. as known in the art. As another example, expression of the transgene is enhanced, or increased, augmented, or stronger, in cone cells comprising a polynucleotide cassette comprising an enhancer sequence disclosed herein than in cone cells that carry the transgene operably linked to a different enhancer sequence. As another example, expression of the transgene is enhanced, or increased, augmented, or stronger, in cone cells comprising a polynucleotide cassette encoding a 5′UTR disclosed herein than in cone cells that carry the transgene operably linked to a different 5′UTR coding sequence. As another example, expression of the transgene is enhanced, or increased, augmented, or stronger, in cone cells comprising a polynucleotide cassette comprising an intron as disclosed herein than in cone cells that carry the transgene operably linked to a different intronic sequence as known in the art. Exemplary sequences comprising elements (e.g., promoters, enhancer sequences, 5′UTRs, and intons) that may be used as references for comparison include sequences encompassed by the native L-opsin promoter (SEQ ID NO:1) and variants thereof, sequences encompassed by the synthetic promoter pR2.1 (SEQ ID NO:50) and variants thereof (e.g. pR1.7, pR1.5, pR1.1) as disclosed in, e.g. US Application No. 2013/0317091, and sequences encompassed by the IRBP/GNAT2 promoter (US Applicaton No. 2014/0275231).

Without wishing to be bound by theory, enhanced expression of a transgene in cells is believed to be due to a faster build-up of gene product in the cells or a more stable gene product in the cells. Thus, enhanced expression of a transgene by the polynucleotide cassettes of the subject disclosure may be observed in a number of ways. For example, enhanced expression may be observed by detecting the expression of the transgene following contact of the polynucleotide cassette to the cone cells sooner, e.g. 7 days sooner, 2 weeks sooner, 3 weeks sooner, 4 weeks sooner, 8 weeks sooner, 12 weeks sooner, or more, than expression would be detected if the transgene were operably linked to comparable regulatory elements, e.g. as known in the art. Enhanced expression may also be observed as an increase in the amount of gene product per cell. For example, there may be a 2-fold increase or more, e.g. a 3-fold increase or more, a 4-fold increase or more, a 5-fold increase or more, or a 10-fold increase or more in the amount of gene product per cone cell. Enhanced expression may also be observed as an increase in the number of cone cells that express detectable levels of the transgene carried by the polynucleotide cassette. For example, there may be a 2-fold increase or more, e.g. a 3-fold increase or more, a 4-fold increase or more, a 5-fold increase or more, or a 10-fold increase or more in the number of cone cells that express detectable levels of the transgene. As another example, the polynucleotide of the present invention may promote detectable levels of the transgene in a greater percentage of cells as compared to a conventional polynucleotide cassette; for example, where a conventional cassette may promote detectable levels of transgene expression in, for example, less than 5% of the cone cells in a certain region, the polynucleotide of the present invention promotes detectable levels of expression in 5% or more of the cone cells in that region; e.g. 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more, in some instances 50% or more, 55% or more; 60% or more, 65% or more, 70% or more, or 75% or more, for example 80% or more, 85% or more, 90% or more, or 95% or more of the cone cells that are contacted, will express detectable levels of gene product. Enhanced expression may also be observed as an alteration in the viability and/or function of the cone cells, e.g. as measured using assessment tools such as fundus photography, OCT, adaptive optics, cERG, color vision tests, visual acuity tests, and the like, as known in the art and as described herein.

The polynucleotide cassettes of the present disclosure typically comprise a promoter region. Any suitable promoter region or promoter sequence therein can be used in the subject polynucleotide cassettes, so long as the promoter region promotes expression of a coding sequence in retinal cone cells. In some embodiments, the promoter specifically promotes expression of the gene in mammalian retinal cone cell; more preferably primate retinal cone cells; more preferably in Catarrhini retinal cone cells; even more preferably in human retinal cone cells. By “specifically” it is meant that the promoter predominately promotes expression of the gene in the target cells as compared to other cell types. Thus, for example, when a promoter region that specifically promotes expression in cone cells is employed, more than 50% of the expression, for example, at least any of 60%, 65%, 70% or 75% or more of the expression, e.g. at least any of 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 97%, 98%, 99%, 99.5%, or more of expression of the gene after delivery of the subject polunucleotide cassette to the eye will be in cone cells.

Exemplary suitable promoter regions include the promoter region for any cone-specific gene, such as a 492 L-opsin promoter region (SEQ ID NO:1), a 491 L-opsin promoter region (SEQ ID NO:53), a 496 L-opsin promoter region (SEQ ID NO:79), an M-opsin promoter region (SEQ ID NO:2, SEQ ID NO:54), a minimal M-opsin promoter region (SEQ ID NO:55, SEQ ID NO:93), a core M-opsin promoter sequence as disclosed for the first time herein (SEQ ID NO:80), an S-opsin promoter region (SEQ ID NO:3), an hRK promoter region, and a cone arrestin promoter region; or portions or variants thereof which retain activity promoting the expression of a gene in cone cells. Nonlimiting examples of portions, or fragments, of promoter regions that find use in the subject polynucleotide cassetttes include promoter sequence immediately upstream of the 5′UTR, and canonical binding sequences for transcription factors as known in the art. Such portions, or fragments, may be readily determined using any convenient method as known in the art or described herein. For example, the promoter sequence immediately upstream of the 5′UTR in SEQ ID NO:54 and SEQ ID NO:55 may readily determined by in silico evaluation of the sequence as consisting essentially of nucleotides 1-406 of SEQ ID NO:54 or nucleotides 1-154 of SEQ ID NO:55 using publicly available tools such as, e.g. the UCSC genome BLAT browser; or by empirical testing through operable linkage with a reporter gene and introduction into cone cells, e.g. as described in the working examples herein. Shorter promoter sequences are, in some embodiments, preferable to longer promoter sequences, as they provide for more space in the vector for other nucleotide elements. In some embodiments, the promoter region is less than 492 base pairs in length. For example, in some embodiments, the functional fragment does not comprise nucleotides 1-10 or more of SEQ ID NO:1, for example, the functional fragment does not comprise nucleotides 1-20 or more, nucleotides 1-30 or more, nucleotides 1-40 or more, nucleotides 1-50 or more of SEQ ID NO:1, e.g. nucleotides 1-60 or more, nucleotides 1-70 or more, nucleotides 1-80 or more, nucleotides 1-90 or more, nucleotides 1-100 or more of SEQ ID NO:1, in some instances nucleotides 1-120 or more, nucleotides 1-140 or more, nucleotides 1-160 or more, nucleotides 1-180 or more, nucleotides 1-200 or more, nucleotides 1-220 or more, nucleotides 1-240 or more, or about nucleotides 1-260 of SEQ ID NO:1. Any suitable method for identifying a promoter region capable of driving expression in mammalian or primate cone cells can be used to identify promoter regions and promoter sequences therein that find use in the polynucleotide cassettes of the present disclosure.

In some embodiments, the promoter region of the subject polynucleotide cassette comprises one of the promoter regions disclosed herein, e.g. a 492 L-opsin promoter region (SEQ ID NO:1), a 491 L-opsin promoter region (SEQ ID NO:53), a 496 L-opsin promoter region (SEQ ID NO:79), an M opsin promoter region (SEQ ID NO:2, SEQ ID NO:54), a minimal M opsin promoter region (SEQ ID NO:55, SEQ ID NO:93), the core M-opsin promoter sequence disclosed herein (SEQ ID NO:80), or the S opsin promoter region (SEQ ID NO:3), or a functional fragment or variant thereof, e.g. a sequence having an identity of 75% or more, e.g. 80% or more, 85% or more, 90% or more, or 95% or more, (e.g., 80%, 85%, 90% Or 95%), to an aforementioned sequence or functional fragment thereof. In some embodiments, the promoter sequence of the subject polynucleotide cassette consists essentially of one of the promoter regions disclosed herein, i.e. SEQ ID NO:1, SEQ ID NO:53, SEQ ID NO:79, SEQ ID NO:2, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:93, SEQ ID NO:80, or SEQ ID NO:3, or a functional fragment or variant thereof, e.g. a sequence having an identity of 75% or more, e.g. 80%, or more 85% or more, 90% or more, or 95% or more, (e.g., 80%, 85%, 90% Or 95%), to the full length of an aforementioned sequence plus or minus 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotides, or functional fragment thereof. In some embodiments, the promoter region of the subject polynucleotide cassette consists of one of the promoter regions disclosed herein, i.e. SEQ ID NO:1, SEQ ID NO:53, SEQ ID NO:79, SEQ ID NO:2, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:93, SEQ ID NO:80, or SEQ ID NO:3, or a functional fragment or variant thereof, e.g. a sequence having an identity of 75% or more, e.g. 80%, 85%, 90%, 95% or more, to the full length of an aforementioned sequence or functional fragment thereof. In certain embodiments, the promoter region consists essentially of SEQ ID NO:74. In some such embodiments, the promoter sequence consists essentially of SEQ ID NO:80. In some embodiments, the promoter results in enhanced expression in cone cells compared to other promoters known in the art, e.g., the synthetic promoters pR2.1, pR1.7,pR1.1, and IRBP/GNAT2.

In some embodiments, the polynucleotide cassette further comprises an enhancer element. Enhancers are nucleic acid elements known in the art to enhance transcription, and can be located anywhere in association with the gene they regulate, e.g. upstream, downstream, within an intron, etc. Any enhancer element can be used in the polynucleotide cassettes and gene therapy vectors of the present disclosure, so long as it enhances expression of the gene when used in combination with the promoter. In a preferred embodiment, the enhancer element is specific for retinal cone cells; more preferably, it is specific for primate retinal cone cells; more preferably in Catarrhini retinal cone cells; even more preferably in human retinal cone cellsBy “specifically” it is meant that the enhancer predominately enhances expression of the gene in the target cells compared to other cell types. Thus, for example, when an enhancer that specifically enhances expression in cone cells is employed, more than 50% of the expression, for example, at least any of 60%, 65%, 70%, 75% or more of the expression, e.g., at least 80%, and preferably 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 97%, 98%, 99%, 99.5%, or more of expression of the gene after delivery of the vector to the eye will be in cone cells.

Exemplary enhancer regions that find use in the polynucleotide cassettes of the present disclosure include those that comprise, consist essentially of, or consist of the enhancer region for any cone-specific gene or fragments or variants thereof which retain enhancer activity. For example, the L/M minimal opsin enhancer, referred to as the Locus Control Region (LCR) (Wang et al., 1992. Neuron 9: 429-440) (SEQ ID NO:52) can be used to enhance gene expression in cone cells; its absence results in blue cone monochromacy (Nathans et al., 1989; Science, 245: 831-838). The LCR has been shown to be useful in gene therapy, for example with AAV vectors (Li et al., Vision Research 48(2008): 332-338). Furthermore, a functional fragment consisting essentially of a 36 bp “core” LCR sequence has been identified that is necessary and sufficient for expression from the opsin promoter in cone cells (Komaromy et al. Targeting gene expression to cones with human cone opsin promoters in recombinant AAV. Gene Ther. 2008; 15(14):1049-55) (SEQ ID NO:51). In some embodiments, the enhancer of the polynucleotide cassette comprises SEQ ID NO:51 or SEQ ID NO:52. In certain embodiments, the enhancer of the polynucleotide cassette consists essentially of SEQ ID NO:51 or SEQ ID NO:52.

L/M enhancer elements of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, or more nucleotides that comprise one or more copies of the L/M minimal opsin enhancer, and the full L/M opsin enhancer, or other portions or variants thereof which retain activity enhancing expression of genes in a cone-specific manner find use in the present compositions. Any suitable method for identifying enhancer sequences capable of driving expression in primate cone cells can be used to identify such enhancers, as will be understood by those of skill in the art based on the teachings herein.

The length of the promoter and enhancer regions can be of any suitable length for their intended purpose, and the spacing between the promoter and enhancer regions can be any suitable spacing to promote cone-specific expression of the gene product. In various preferred embodiments, the enhancer is located 0-1500; 0-1250; 0-1000; 0-750; 0-600; 0-500; 0-400; 0-300; 0-200; 0-100; 0-90; 0-80; 0-70; 0-60; 0-50; 0-40; 0-30; 0-20; or 0-10 nucleotides upstream of the promoter. The promoter can be any suitable distance upstream of the encoded gene.

In some embodiments, the subject polynucleotide cassette comprises a sequence encoding a 5′ untranslated region, i.e. polynucleotide sequence encoding an untranslated region 5′ to the coding sequence, also called the 5′UTR. In an expression cassette, the 5′UTR is known in the art as the sequence between the transcription initiation site and the Kozak sequence where protein translation begins. Secondary mRNA structure of the 5′UTR is known to affect transcription levels. Specifically, for enhanced gene expression, the sequence of the 5′UTR region in the present invention is selected to minimize or avoid secondary structures and upstream AUG (uAUG) codons which are known to decrease translation efficiency due to inefficient ribosome scanning and false translational starts (Kozak, 1995. PNAS 92:2662). See Davuluri et al., Genome Research, 2000: 10 (11); 1807-1816. For example, the 5′UTR sequence from the human gene HSP70 (SEQ ID NO:58) has been identified for its unusual ability to enhance mRNA translation, possibly due to an IRES mechanism (Rubtsova et al., 2003. PNAS 278(25): 22350-22356; Vivinus et al, 2001. Eur J Biochem. 268: 1908-1917). Any 5′ UTR can be used, but ideally the sequence of the 5′UTR has minimal secondary mRNA structure and upstream AUG sequences. Put another way, in some embodiments, the sequence between the transcription initiation site and the translation initiation site of the polynucleotide cassette does not contain the polynucleotide ATG. In some embodiments, the 5′ UTR comprises, consists essentially, or consists of SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:84, SEQ ID NO:85, SEQ ID NO:86, SEQ ID NO:87, SEQ ID NO:88, or SEQ ID NO:89; or a functional fragment or variant thereof, for example, a polynucleotide sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:84, SEQ ID NO:85, SEQ ID NO:86, SEQ ID NO:87, SEQ ID NO:88, and SEQ ID NO:89, or a fragment thereof. In some embodiments, some or all of the 5′UTR sequence is comprised by a promoter region as disclosed in, for example, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO:55, or SEQ ID NO:79. In other embodiments, the 5′UTR is not comprised by the promoter region; see, e.g. the core promoter sequence SEQ ID NO:84, which does not encode for 5′ UTR sequence. In some embodiments, the 5′UTR sequence is heterologous to the promoter sequence. In various preferred embodiments, the 3′ end of the UTR is 0-20; 0-15; 0-10; 0-9; 0-8; 0-7; 0-6; or 0-5 nucleotides upstream of the coding sequence, and its 5′ end is 0-20; 0-15; 0-10; 0-9; 0-8; 0-7; 0-6; or 0-5 nucleotides downstream of the proximal promoter region. In some embodiments, the 5′UTR element results in enhanced expression in cone cells compared to other 5′UTRs known in the art, e.g., the 5′UTRs comprised by the synthetic promoters pR2.1, pR1.7, pR1.1, and IRBP/GNAT2.

In some embodiments, the subject polynucleotide cassette further comprises an intron comprising a splice donor/acceptor region. In some embodiments, the intron is located downstream of the promoter region and is located upstream of the translation initiation sequence of the gene, i.e. the intron is located within the 5′UTR. In other embodiments, the intron is located downstream of the translation initiation sequence of the gene, i.e. the intron is located within the coding sequence. As is generally known in the art, introns are DNA polynucleotides that are transcribed into RNA and removed during mRNA processing through intron splicing. Polynucleotide cassettes containing introns generally have higher expression than those without introns. Introns can stimulate expression between 2- and 500-fold (Buchman and Berg, 1988. Mol Cel Bio, 8(10): 4395). Efficiently spliced introns contain a pre-splice donor, branchpoint, and Py rich region (Senapathy et al, 1990; Meth. Enzymol. 183, 252-78; Wu and Krainer, 1999; Mol Cell Biol 19(5):3225-36). 5′ introns are generally more efficient compared to introns at the 3′ end (Huang and Gorman, 1990; Mol Cell Bio, 10:1805). Although introns are known generally to increase the level of gene expression, the specific increase (if any) of a given cDNA is empirical and must be tested; for example the chimeric intron in the pSI vector increases CAT expression by 21-fold, but luciferase expression by only 3-fold.

Any intron can be used in the subject polynucleotide cassettes, so long as it comprises a splice donor/acceptor region recognized in mammalian or in primate cone cells, so that the intron can be spliced out of the resulting mRNA product. In one embodiment, the intron comprises, consists essentially of, or consists of an SV40 intron according to SEQ ID NO:5. In another embodiment, the intron comprises, consists essentially of, or consists of the chimeric intron from pSI (SEQ ID NO:60) or a variant thereof. In another embodiment, the intron comprises, consists essentially of, or consists of the CMV intron A or a variant thereof. In yet another embodiment, the intron comprises, consists essentially of, or consists of the pR2.1 intron (SEQ ID NO:59) or a variant thereof, or alternatively, the rabbit or human beta globin intron (Xu et al, 2001, Gene 272:149; Xu et al. 2002; J Control Rel 81:155) or a variant thereof. In some such embodiments, the intron comprises a sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:59, and SEQ ID NO:60. Typically, the intron is heterologous to the promoter region and/or the 5′UTR.

In some embodiments, the intron resides within a 5′UTR. In other words, the DNA sequence encoding the 5′UTR is interrupted by intronic DNA sequence. For example, the coding sequence for the 5′UTR that is SEQ ID NO:84 may be encoded in two parts, e.g. SEQ ID NO:85 and SEQ ID NO:86, with an intronic sequence between them. As another example, the coding sequences for the 5′UTR that is SEQ ID NO:88 may be encoded in two parts, e.g. SEQ ID NO:89 and SEQ ID NO:73, with an intronic sequence between them. In various embodiments, the 3′ end of the intron is 0-20; 0-15; 0-10; 0-9; 0-8; 0-7; 0-6; or 0-5 nucleotides upstream of the gene, and its 5′ end is 0-20; 0-15; 0-10; 0-9; 0-8; 0-7; 0-6; or 0-5 nucleotides downstream of the proximal promoter region. In other embodiments, the intron resides within the coding sequene of the gene.

In some embodiments, the polynucleotides cassettes of the present disclosure comprise a translation initiation sequence, also know as a “Kozak sequence” or “Kozak translation initiation sequence. This is the nucleic acid sequence where the ribosome attaches and translation begins. Examples include ACCATGG (Kozak, 1986. Cell, 44:283-292) and (GCC)GCC(A/G)CCATGG (Kozak, 1987. Nucl Acid Res; 15(20): 8125) (SEQ ID NO:73). Any suitable Kozak sequence can be used in the polynucleotide cassette, preferably selected to increase expression of the coding sequence in retinal cone cells. In one embodiment, the translation initiation sequence comprises SEQ ID NO:72. In an alternative embodiment, the translation initiation sequence comprises SEQ ID NO:73. In some embodiments, the Kozak element results in enhanced expression in cone cells compared to other Kozak sequences known in the art, e.g., the Kozak sequences comprised by the synthetic promoters pR2.1, pR1.7, pR1.1, and IRBP/GNAT2.

In some aspects of the present invention, the subject polynucleotide cassettes are used to deliver a gene to cone cells of an animal, e.g. to determine the effect that the gene has on cell viability and/or function, to treat a cone cell disorder, etc. Accordingly, in some embodiments, the polynucleotide cassettes of the present disclosure further comprise a gene to be delivered as a transgene to cone cells of an animal in vitro or in vivo. The gene coding sequence is typically operatively linked to the promoter region of the subject polynucleotide cassette, and in instances in which an an enhancer element is present, to the enhancer element of the subject polynucleotide cassette, such that the promoter and optionally enhancer elements promote the expression of the coding sequence or cDNA in cone cells of the subject.

The coding sequence to be expressed in the cone cells can be any polynucleotide sequence, e.g. gene or cDNA that encodes a gene product, e.g. polypeptide or RNA-based therapeutic (siRNA, antisense, ribozyme, shRNA, etc.). The coding sequence may be heterologous to the promoter sequence and/or 5′UTR sequence to which it is operably linked, i.e. not naturally operably associated with it. Alternatively, the coding sequence may be endogenous to the promoter sequence and/or 5′UTR sequence to which it is operably linked, i.e. is associated in nature with that promoter or 5′UTR. The gene product may act intrinsically in the cone cell, or it may act extrinsically, e.g. it may be secreted. For example, when the transgene is a therapeutic gene, the coding sequene may be any gene that encodes a desired gene product or functional fragment or variant thereof that can be used as a therapeutic for treating a cone cell disease or disorder, or as a means to otherwise enhance vision, including but not limited to promoting tetrachromatic color vision. In various preferred embodiments, the transgene encodes a therapeutic protein or functional fragment or variant thereof selected from the group consisting of:

-   -   (a) SEQ ID NO:7 (SEQ ID NO:6) Homo sapiens opsin 1 (cone         pigments), short-wave-sensitive (OPN1SW), mRNA NCBI Reference         Sequence: NM_001708.2;     -   (b) SEQ ID NO:9 (SEQ ID NO:8) Homo sapiens opsin 1 (cone         pigments), medium-wave-sensitive (OPN1MW), mRNA NCBI Reference         Sequence: NM_000513.2;     -   (c) SEQ ID NO:11 (SEQ ID NO:10) Homo sapiens opsin 1 (cone         pigments), long-wave-sensitive (OPN1LW), mRNA NCBI Reference         Sequence: NM_020061.4;     -   (d) SEQ ID NO:13 (SEQ ID NO:12) ATP binding cassette retina gene         (ABCR) gene (NM_000350);     -   (e) SEQ ID NO:15 (SEQ ID NO:14) retinal pigmented         epithelium-specific 65 kD protein gene (RPE65) (NM._000329);     -   (f) SEQ ID NO:17 (SEQ ID NO:16) retinal binding protein 1 gene         (RLBP1) (NM._000326);     -   (g) SEQ ID NO:19 (SEQ ID NO:18) peripherin/retinal degeneration         slow gene, (NM_000322);     -   (h) SEQ ID NO:21 (SEQ ID NO:20) arrestin (SAG) (NM_000541);     -   (i) SEQ ID NO:23 (SEQ ID NO:22) alpha-transducin (GNAT1)         (NM_000172);     -   (j) SEQ ID NO:24 guanylate cyclase activator 1A (GUCA1A)         (NP_000400.2);     -   (k) SEQ ID NO:25 retina specific guanylate cyclase (GUCY2D),         (NP_000171.1);     -   (l) SEQ ID NO:26 & 27 alpha subunit of the cone cyclic         nucleotide gated cation channel (CNGA3) (NP_001073347.1 or         NP_001289.1);     -   (m) SEQ ID NO:28 Human cone transducin alpha subunit (incomplete         achromotopsia);     -   (n) SEQ ID NO:29 cone cGMP-specific 3′,5′-cyclic         phosphodiesterase subunit alpha′, protein (cone dystrophy type         4);     -   (o) SEQ ID NO:30 retinal cone rhodopsin-sensitive cGMP         3′,5′-cyclic phosphodiesterase subunit gamma, protein (retinal         cone dystrophy type 3A);     -   (p) SEQ ID NO:31 cone rod homeobox, protein (Cone-rod         dystrophy);     -   (q) SEQ ID NO:32 cone photoreceptor cyclic nucleotide-gated         channel beta subunit, protein (achromatopsia);     -   (r) SEQ ID NO:33 cone photoreceptor cGMP-gated cation channel         beta-subunit, protein (total color blindness, for example, among         Pingelapese Islanders);     -   (s) SEQ ID NO:35 (SEQ ID NO:34) retinitis pigmentosa 1         (autosomal dominant) (RP 1);     -   (t) SEQ ID NO:37 (SEQ ID NO:36) retinitis pigmentosa GTPase         regulator interacting protein 1 (RPGRIP 1);     -   (u) SEQ ID NO:39 (SEQ ID NO:38) PRP8;     -   (v) SEQ ID NO:41 (SEQ ID NO:40) centrosomal protein 290 kDa         (CEP290);     -   (w) SEQ ID NO:43 (SEQ ID NO:42) IMP (inosine 5′-monophosphate)         dehydrogenase 1 (IMPDH1), transcript variant 1;     -   (x) SEQ ID NO:45 (SEQ ID NO:44) aryl hydrocarbon receptor         interacting protein-like 1 (AIPL1), transcript variant 1;     -   (y) SEQ ID NO:47 (SEQ ID NO:46) retinol dehydrogenase 12         (all-trans/9-cis/11-cis) (RDH12);     -   (z) SEQ ID NO:49 (SEQ ID NO:48) Leber congenital amaurosis 5         (LCA5), transcript variant 1; and     -   (aa) exemplary OPN1LW/OPN1MW2 polymorphs (compared to OPN1LW (L         opsin) polypeptide sequence; the amino acid to the left of the         number is the residue present in the L opsin sequence; the         number is the reside number in L opsin, and the reside to the         right of the number is the variation from L opsin. Polymorphs         according to these embodiments may comprise one or more of the         amino acid substitutions selected from Thr65Ile; Ile111Val;         Ser116Tyr; Leu153Met; Ile171Val; Ala174Val; Ile178Val;         Ser180Ala; Ile230Thr; Ala233Ser; Val236Met; Ile274Val;         Phe275Leu; Tyr277Phe; Val279Phe; Thr285Ala; Pro298Ala;         Tyr309Phe;     -   (ab) Additional Opsin Sequence Variation 1 (SEQ ID NO:61);     -   (ac) Additional Opsin Sequence Variation 2 (SEQ ID NO:62);     -   (ad) Additional Opsin Sequence Variation 3 (SEQ ID NO:63);     -   (ae) Additional Opsin Sequence Variation 4 (SEQ ID NO:64);     -   (af) Additional Opsin Sequence Variation 5 (SEQ ID NO:65);     -   (ag) Additional Opsin Sequence Variation 6 (SEQ ID NO:65);     -   (ah) Additional Opsin Sequence Variation 7 (SEQ ID NO:66);     -   (ai) Additional Opsin Sequence Variation 8 (SEQ ID NO:67);     -   (aj) Additional Opsin Sequence Variation 9 (SEQ ID NO:68);     -   (ak) hCHR2 (channel rhodopsin) (SEQ ID NO:69);     -   (al) NpHR (halorhodopsin) (SEQ ID NO:70); and     -   (am) eGFP (SEQ ID NO:71).

In some embodiments, the coding sequence encoded by the transgene encodes a polypeptide having at least 85% sequence identity to a polypeptide encoded by a sequence disclosed above or herein, for example at least 90% sequence identity, e.g. at least 95% sequence identity, at least 98% sequence identity, or at least 99% sequence identity. Thus, for example, the coding sequence encodes a cone opsin having at least 85%, at least 90%, at least 95% identity, at least 98% sequence identity, or at least 99% sequence identity, to the polypeptide encoded by OPN1LW, OPNIMW, or OPN1SW. In some embodiments, the coding sequence has a sequence identity of at least 85%, 90%, 95%, 98% or at least 99% to SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, SEQ ID NO:16, SEQ ID NO:18, SEQ ID NO:20, SEQ ID NO:22, SEQ ID NO:34, SEQ ID NO:36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44, SEQ ID NO:46, SEQ ID NO:48, SEQ ID NO:61, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ ID NO:65, SEQ ID NO:66, SEQ ID NO:67, SEQ ID NO:68, SEQ ID NO:69, SEQ ID NO:70, or SEQ ID NO:71.

The proteins recited in (a)-(c) and (aa-aj) are all involved in color vision. The exemplary polymorphs include ones at positions 65, 116, 180, 230, 233, 277, 285, and 309 that affect the spectra of the pigments in cone cells expressing them. Positions 274, 275, 277, 279, 285, 298 and 309 together distinguish L opsin from M opsin.

The proteins recited (d)-(z) are exemplary eye disease-associated genes such as in retinitis pigmentosa (polypeptides “e”-“l”, “s”-“y”), incomplete achromatopsia (polypeptide “m”), Stargardt's (polypeptide “d”); Leber congenital amaurosis (polypeptide “z”); cone dystrophy, such as cone dystrophy type 4 (polypeptide “n”); retinal cone dystrophy; for example, retinal cone dystrophy type 3A (polypeptide “o”); Cone-rod dystrophy (polypeptide “p”); achromatopsia (polypeptide “q’); and total color blindness, for example, among Pingelapese Islanders (polypeptide “r”).

In one embodiment of the invention, the transgene coding sequence is modified, or “codon optimized” to enhance expression by replacing infrequently represented codons with more frequently represented codons. The coding sequence is the portion of the mRNA sequence that encodes the amino acids for translation. During translation, each of 61 trinucleotide codons are translated to one of 20 amino acids, leading to a degeneracy, or redundancy, in the genetic code. However, different cell types, and different animal species, utilize tRNAs (each bearing an anticodon) coding for the same amino acids at different frequencies. When a gene sequence contains codons that are infrequently represented by the corresponding tRNA, the ribosome translation machinery may slow, impeding efficient translation. Expression can be improved via “codon optimization” for a particular species, where the coding sequence is altered to encode the same protein sequence, but utilizing codons that are highly represented, and/or utilized by highly expressed human proteins (Cid-Arregui et al., 2003; J. Virol. 77: 4928). In one aspect of the present invention, the coding sequence of the transgene is modified to replace codons infrequently expressed in mammal or in primates with codons frequently expressed in primates. For example, in some embodiments, the coding sequence encoded by the transgene encodes a polypeptide having at least 85% sequence identity to a polypeptide encoded by a sequence disclosed above or herein, for example at least 90% sequence identity, e.g. at least 95% sequence identity, at least 98% identity, at least 99% identity, wherein at least one codon of the coding sequence has a higher tRNA frequency in humans than the corresponding codon in the sequence disclosed above or herein.

In an additional embodiment of the invention, the transgene coding sequence is modified to enhance expression by termination or removal of open reading frames (ORFs) that do not encode the desired transgene. An open reading frame (ORF) is the nucleic acid sequence that follows a start codon and does not contains a stop codons. ORFs may be in the forward or reverse orientation, and may be “in frame” or “out of frame” compared with the gene of interest. Such open reading frames have the potential to be expressed in an expression cassette alongside the gene of interest, and could lead to undesired adverse effects. In one aspect of the present invention, the coding sequence of the transgene has been modified to remove open reading frames by further altering codon usage. This was done by eliminating start codons (ATG) and introducing stop codons (TAG, TAA, or TGA) in reverse orientation or out-of-frame ORFs, while preserving the amino acid sequence and maintaining highly utilized codons in the gene of interest (i.e., avoiding codons with frequency<20%). In the present invention, the transgene coding sequence may be optimized by either of codon optimization and removal of non-transgene ORFs or using both techniques. As will be apparent to one of ordinary skill in the art, it is preferable to remove or minimize non-transgene ORFs after codon optimization in order to remove ORFs introduced during codon optimization. Examples of codon optimization and removal of ORFs are shown in FIGS. 3A-3C.

In some embodiments, the polynucleotide cassette of the present invention further comprises a polyadenylation region. As is understood in the art, RNA polymerase II transcripts are terminated by cleavage and additional of a polyadenylation region, also known as a poly A signal, poly A region or poly A tail. The poly A region contains multiple consecutive adenosine monophosphates, often with repeats of the motif AAUAAA. Several efficient polyadenylation sites have been identified, including those from SV40, bovine growth hormone, human growth hormone and rabbit beta globin (Xu et al, 2001; Gene 272: 149; Xu et al., 2002; J Control Rel. 81:155). The most efficient polyA signal for expression of a transgene in cone cells may depend on the cell type and species of interest and the particular vector used. In some embodiments of the invention, the polynucleotide cassette comprises, consists essentially of, or consists of the polyA region selected from the group consisting of SEQ ID NO:74, SEQ ID NO:75, SEQ ID NO:76, SEQ ID NO:77, SEQ ID NO:78, SEQ ID NO:90 or SEQ ID NO:91 or functional fragment or variant thereof of any of the preceding sequences. In certain embodiments, the polyA region comprises SEQ ID NO:90 or a variant thereof. In some such embodiments, the polyA region consists essentially of SEQ ID NO:90 or a variant thereof.

As will be appreciated by the ordinarily skilled artisan, two or more of the aforementioned polynucleotide elements may be combined to create the polynucleotide cassettes of the present disclosure. Thus, for example, the subject polynucleotide cassette may comprise a promoter region comprising an improved promoter sequence in operable linkage with an improved 5′UTR sequence, for example SEQ ID NO:80 in operable combination with SEQ ID NO:84 or SEQ ID NO:85, see, e.g. SEQ ID NO:2, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:93, SEQ ID NO:94, or SEQ ID NO:95. As another example, the subject polynucleotide cassette may comprise an improved enhancer sequence or region in operable linkage with an improved promoter sequence or region, for example SEQ ID NO:51 or SEQ ID NO:52 in operable combination with SEQ ID NO:80, SEQ ID NO:2, SEQ ID NO:54, SEQ ID NO:55, or SEQ ID NO:93; see, e.g. SEQ ID NO:92 or SEQ ID NO:95. As another example, the subject polynucleotide cassette may comprise an improved 5′UTR sequence in operable linkage with an improved intron sequence, for example SEQ ID NO:84 or SEQ ID NO:86 in operable combination with SEQ ID NO:60; see, e.g. SEQ ID NO:94 or SEQ ID NO:95. As another example, the subject polynucleotide cassette may comprise an improved 5′UTR sequence in operable linkage with an improved intron sequence and an improved Kozak sequence, for example, SEQ ID NO:84 or SEQ ID NO:86 in operable combination with SEQ ID NO:60 and with SEQ ID NO:73; see, e.g. SEQ ID NO:95. As another example, the subject polynucleotide cassette may comprise an improved enhancer, improved promoter, improved 5′UTR, improved intron, improved kozak and improved polyA region in operable linkage; see, e.g. SEQ ID NO:95. Other combinations of elements both as disclosed herein or as known in the art will be readily appreciated by the ordinarily skilled artisan.

Additionally, as will be recognized by one of ordinary skill in the art, the polynucleotide cassettes may optionally contain other elements including, but not limited to restriction sites to facilitate cloning and regulatory elements for a particular gene expression vector. Examples of regulatory sequence include ITRs for AAV vectors, bacterial sequences for plasmid vectors, attP or attB sites for phage integrase vectors, and transposable elements for transposons.

Gene Therapy Vectors

As alluded to above, in some aspects of the present invention, the subject polynucleotide cassettes are used to deliver a gene to cone cells of an animal, e.g. to determine the effect that the gene has on cell viability and/or function, to treat a cone cell disorder, etc. Accordingly, in some aspects of the invention, the composition that provides for the expression of a transgene in cone cells is a gene delivery vector, wherein the gene delivery vector comprises the polynucleotide cassettes of the present disclosure.

Any convenient gene therapy vector that finds use delivering polynucleotide sequences to cone cells is encompassed by the gene delivery vectors of the present disclosure. For example, the vector may comprise single or double stranded nucleic acid, e.g. single stranded or double stranded DNA. For example, the gene delivery vector may be a naked DNA, e.g. a plasmid, a minicircle, etc. As another example, the gene delivery vector may be a virus, e.g. an adenovirus, an adeno-associated virus, or a retrovirus, e.g. Moloney murine leukemia virus (M-MuLV), Moloney murine sarcoma virus (MoMSV), Harvey murine sarcoma virus (HaMuSV), murine mammary tumor virus (MuMTV), gibbon ape leukemia virus (GaLV), feline leukemia virus (FLV), spumavirus, Friend murine leukemia virus, Murine Stem Cell Virus (MSCV) and Rous Sarcoma Virus (RSV)) or lentivirus. While embodiments encompassing the use of adeno-associated virus are described in greater detail below, it is expected that the ordinarily skilled artisan will appreciate that similar knowledge and skill in the art can be brought to bear on non-AAV gene therapy vectors as well. See, for example, the discussion of retroviral vectors in, e.g., U.S. Pat. No. 7,585,676 and U.S. Pat. No. 8,900,858, and the discussion of adenoviral vectors in, e.g. U.S. Pat. No. 7,858,367, the full disclosures of which are incorporated herein by reference.

In some embodiments, the gene delivery vector is a recombinant adeno-associated virus (rAAV). In such embodiments, the subject polynucleotide cassette is flanked on the 5′ and 3′ ends by functional AAV inverted terminal repeat (ITR) sequences. By “functional AAV ITR sequences” is meant that the ITR sequences function as intended for the rescue, replication and packaging of the AAV virion. Hence, AAV ITRs for use in the gene delivery vectors of the invention need not have a wild-type nucleotide sequence, and may be altered by the insertion, deletion or substitution of nucleotides or the AAV ITRs may be derived from any of several AAV serotypes, e.g. AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10. Preferred AAV vectors have the wild type REP and CAP genes deleted in whole or part, but retain functional flanking ITR sequences.

In such embodiments, the subject polynucleotide cassette is encapsidated within an AAV capsid, which may be derived from any adeno-associated virus serotype, including without limitation, AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, etc. For example, the AAV capsid may be a wild type, or native, capsid. Wild type AAV capsids of particular interest include AAV2, AAV5, and AAV9. However, as with the ITRs, the capsid need not have a wild-type nucleotide sequence, but rather may be altered by the insertion, deletion or substitution of nucleotides in the VP1, VP2 or VP3 sequence, so long as the capsid is able to transduce cone cells. Put another way, the AAV capsid may be a variant AAV capsid. Variant AAV capsids of particular interest include those comprising a peptide insertion within residues 580-600 of AAV2 or the corresponding residues in another AAV, e.g. LGETTRP, NETITRP, KAGQANN, KDPKTTN, KDTDTTR, RAGGSVG, AVDTTKF, orSTGKVPN, as disclosed in US Application No. US 2014/0294771, the full disclosure of which is incorporated by reference herein. In some embodiments, the AAV vector is a “pseudotyped” AAV created by using the capsid (cap) gene of one AAV and the rep gene and ITRs from a different AAV, e.g. a pseudotyped AAV2 created by using rep from AAV2 and cap from AAV1, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, or AAV9 together with a plasmid containing a vector based on AAV2. For example, the AAV vector may be rAAV2/1, rAAV2/3, rAAV2/4, rAAV2/5, rAAV2/6, rAAV2/7, rAAV2/8, rAAV2/9, etc. Preferably, the rAAV is replication defective, in that the AAV vector cannot independently further replicate and package its genome. For example, when cone cells are transduced with rAAV virions, the gene is expressed in the transduced cone cells, however, due to the fact that the transduced cone cells lack AAV rep and cap genes and accessory function genes, the rAAV is not able to replicate.

Gene therapy vectors, e.g. rAAV) virions encapsulating the polynucleotide cassettes of the present disclosure, may be produced using standard methodology. For example, in the case of rAAV virions, an AAV expression vector according to the invention may be introduced into a producer cell, followed by introduction of an AAV helper construct, where the helper construct includes AAV coding regions capable of being expressed in the producer cell and which complement AAV helper functions absent in the AAV vector. This is followed by introduction of helper virus and/or additional vectors into the producer cell, wherein the helper virus and/or additional vectors provide accessory functions capable of supporting efficient rAAV virus production. The producer cells are then cultured to produce rAAV. These steps are carried out using standard methodology. Replication-defective AAV virions encapsulating the recombinant AAV vectors of the instant invention are made by standard techniques known in the art using AAV packaging cells and packaging technology. Examples of these methods may be found, for example, in U.S. Pat. Nos. 5,436,146; 5,753,500, 6,040,183, 6,093,570 and 6,548,286, expressly incorporated by reference herein in their entirety. Further compositions and methods for packaging are described in Wang et al. (US 2002/0168342), also incorporated by reference herein in its entirety.

Any suitable method for producing viral particles for delivery of the subject polynucleotide cassettes can be used, including but not limited to those described in the examples that follow. Any concentration of viral particles suitable to effectively transducer cone cells can be prepared for contacting cone cells in vitro or in vivo. For example, the viral particles may be formulated at a concentration of 10⁸ vector genomes per ml or more, for example, 5×10⁸ vector genomes per mL; 10⁹ vector genomes per mL; 5×10⁹ vector genomes per mL, 10¹⁰ vector genomes per mL, 5×10¹⁰ vector genomes per mL; 10¹¹ vector genomes per mL; 5×10¹¹ vector genomes per mL; 10¹² vector genomes per mL; 5×10¹² vector genomes per mL; 10¹³ vector genomes per mL; 1.5×10¹³ vector genomes per mL; 3×10¹³ vector genomes per mL; 5×10¹³ vector genomes per mL; 7.5×10¹³ vector genomes per mL; 9×10¹³ vector genomes per mL; 1×10¹⁴ vector genomes per mL, 5×10¹⁴ vector genomes per mL or more, but typically not more than 1×10¹⁵ vector genomes per mL. Similarly, any total number of viral particles suitable to provide appropriate transduction of retinal cone cells to confer the desired effect or treat the disease can be administered to the mammal or to the primate's eye. In various preferred embodiments, at least 10⁸; 5×10⁸; 10⁹; 5×10⁹, 10¹⁰, 5×10¹⁰; 10¹¹; 5×10¹¹; 10¹²; 5×10¹²; 10¹³; 1.5×10¹³; 3×10¹³; 5×10¹³; 7.5×10¹³; 9×10¹³, 1×10¹⁴ viral particles, or 5×10¹⁴ viral particles or more, but typically not more than 1×10¹⁵ viral particles are injected per eye. Any suitable number of administrations of the vector to the mammal or the primate eye can be made. In one embodiment, the methods comprise a single administration; in other embodiments, multiple administrations are made over time as deemed appropriate by an attending clinician.

The subject viral vector may be formulated into any suitable unit dosage, including, without limitation, 1×10⁸ vector genomes or more, for example, 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², or 1×10¹³ vector genomes or more, in certain instances, 1×10¹⁴ vector genomes, but usually no more than 4×10¹⁵ vector genomes. In some cases, the unit dosage is at most about 5×10¹⁵ vector genomes, e.g. 1×10¹⁴ vector genomes or less, for example 1×10¹³, 1×10¹², 1×10¹¹, 1×10¹⁰, or 1×10⁹ vector genomes or less, in certain instances 1×10⁸ vector genomes or less, and typically no less than 1×10⁸ vector genomes. In some cases, the unit dosage is 1×10¹⁰ to 1×10¹¹ vector genomes. In some cases, the unit dosage is 1×10¹⁰ to 3×10¹² vector genomes. In some cases, the unit dosage is 1×10⁹ to 3×10¹³ vector genomes. In some cases, the unit dosage is 1×10⁸ to 3×10¹⁴ vector genomes.

In some cases, the unit dosage of pharmaceutical composition may be measured using multiplicity of infection (MOI). By MOI it is meant the ratio, or multiple, of vector or viral genomes to the cells to which the nucleic acid may be delivered. In some cases, the MOI may be 1×10⁶. In some cases, the MOI may be 1×10⁵-1×10⁷. In some cases, the MOI may be 1×10⁴-1×10⁸. In some cases, recombinant viruses of the disclosure are at least about 1×10¹, 1×10², 1×10³, 1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸, 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², 1×10¹³, 1×10¹⁴, 1×10¹⁵, 1×10¹⁶, 1×10¹⁷, and 1×10¹⁸ MOI. In some cases, recombinant viruses of this disclosure are 1×10⁸ to 3×10¹⁴ MOI. In some cases, recombinant viruses of the disclosure are at most about 1×10¹, 1×10², 1×10³, 1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸, 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², 1×10¹³, 1×10¹⁴, 1×10¹⁵, 1×10¹⁶, 1×10¹⁷ and 1×10¹⁸ MOI.

In some aspects, the amount of pharmaceutical composition comprises about 1×10⁸ to about 1×10¹⁵ recombinant viruses, about 1×10⁹ to about 1×10¹⁴ recombinant viruses, about 1×10¹⁰ to about 1×10¹³ recombinant viruses, or about 1×10¹¹ to about 3×10¹² recombinant viruses.

In preparing the subject rAAV compositions, any host cells for producing rAAV virions may be employed, including, for example, mammalian cells (e.g. 293 cells), insect cells (e.g. SF9 cells), microorganisms and yeast. Host cells can also be packaging cells in which the AAV rep and cap genes are stably maintained in the host cell or producer cells in which the AAV vector genome is stably maintained and packaged. Exemplary packaging and producer cells are derived from SF-9, 293, A549 or HeLa cells. AAV vectors are purified and formulated using standard techniques known in the art.

For instances in which cone cells are to be contacted in vivo, the subject polynucleotide cassettes or gene delivery vectors comprising the subject polynucleotide cassette can be treated as appropriate for delivery to the eye. In particular, the present invention include pharmaceutical compositions comprising a polynucleotide cassetee or gene delivery vector described herein and a pharmaceutically-acceptable carrier, diluent or excipient. The subject polynucleotide cassettes or gene delivery vector can be combined with pharmaceutically-acceptable carriers, diluents and reagents useful in preparing a formulation that is generally safe, non-toxic, and desirable, and includes excipients that are acceptable for primate use. Such excipients can be solid, liquid, semisolid, or, in the case of an aerosol composition, gaseous. Examples of such carriers or diluents include, but are not limited to, water, saline, Ringer's solutions, dextrose solution, and 5% human serum albumin. Supplementary active compounds can also be incorporated into the formulations. Solutions or suspensions used for the formulations can include a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial compounds such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfate; chelating compounds such as ethylenediaminetetraacetic acid (EDTA); buffers such as acetates, citrates or phosphates; detergents such as Tween 20 to prevent aggregation; and compounds for the adjustment of tonicity such as sodium chloride or dextrose. The pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide.

Pharmaceutical compositions suitable for internal use in the present invention further include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, or phosphate buffered saline (PBS). In somecases, the composition is sterile and should be fluid to the extent that easy syringability exists. In certain embodiments, it is stable under the conditions of manufacture and storage and is preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be, e.g., a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, sodium chloride in the composition. Prolonged absorption of the internal compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.

Sterile solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, methods of preparation are vacuum drying and freeze-drying that yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

In one embodiment, active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially. Liposomal suspensions (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No. 4,522,811.

It is especially advantageous to formulate oral or parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals.

The pharmaceutical compositions can be included in a container, pack, or dispenser, e.g. syringe, e.g. a prefilled syringe, together with instructions for administration.

The pharmaceutical compositions of the invention encompass any pharmaceutically acceptable salts, esters, or salts of such esters, or any other compound which, upon administration to an animal comprising a human, is capable of providing (directly or indirectly) the biologically active metabolite or residue thereof. Accordingly, for example, the disclosure is also drawn to prodrugs and pharmaceutically acceptable salts of the compounds of the invention, pharmaceutically acceptable salts of such prodrugs, and other bio-equivalents.

The term “prodrug” indicates a therapeutic agent that is prepared in an inactive form that is converted to an active form (i.e., drug) within the body or cells thereof by the action of endogenous enzymes or other chemicals and/or conditions.

The term “pharmaceutically acceptable salt” refers to physiologically and pharmaceutically acceptable salts of the compounds of the invention: i.e., salts that retain the desired biological activity of the parent compound and do not impart undesired toxicological effects thereto. A variety of pharmaceutically acceptable salts are known in the art and described, e.g., in in “Remington's Pharmaceutical Sciences”, 17th edition, Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., USA, 1985 (and more recent editions thereof), in the “Encyclopaedia of Pharmaceutical Technology”, 3rd edition, James Swarbrick (Ed.), Informa Healthcare USA (Inc.), NY, USA, 2007, and in J. Pharm. Sci. 66: 2 (1977). Also, for a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002).

Pharmaceutically acceptable base addition salts are formed with metals or amines, such as alkali and alkaline earth metals or organic amines. Metals used as cations comprise sodium, potassium, magnesium, calcium, and the like Amines comprise N—N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, dicyclohexylamine, ethylenediamine, N-methylglucamine, and procaine (see, for example, Berge et al., “Pharmaceutical Salts,” J. Pharma Sci., 1977, 66, 119). The base addition salts of said acidic compounds are prepared by contacting the free acid form with a sufficient amount of the desired base to produce the salt in the conventional manner. The free acid form may be regenerated by contacting the salt form with an acid and isolating the free acid in the conventional manner. The free acid forms differ from their respective salt forms somewhat in certain physical properties such as solubility in polar solvents, but otherwise the salts are equivalent to their respective free acid for purposes of the present invention.

The subject polynucleotide cassette or gene delivery vector, e.g.recombinant virus (virions), can be incorporated into pharmaceutical compositions for administration to mammalian patients, particularly primates and more particularly humans. The subject polynucleotide cassette or gene delivery vector, e.g. virions can be formulated in nontoxic, inert, pharmaceutically acceptable aqueous carriers, preferably at a pH ranging from 3 to 8, more preferably ranging from 6 to 8. Such sterile compositions will comprise the vector or virion containing the nucleic acid encoding the therapeutic molecule dissolved in an aqueous buffer having an acceptable pH upon reconstitution.

In some embodiments, the pharmaceutical composition provided herein comprise a therapeutically effective amount of a vector or virion in admixture with a pharmaceutically acceptable carrier and/or excipient, for example saline, phosphate buffered saline, phosphate and amino acids, polymers, polyols, sugar, buffers, preservatives and other proteins. Exemplary amino acids, polymers and sugars and the like are octylphenoxy polyethoxy ethanol compounds, polyethylene glycol monostearate compounds, polyoxyethylene sorbitan fatty acid esters, sucrose, fructose, dextrose, maltose, glucose, mannitol, dextran, sorbitol, inositol, galactitol, xylitol, lactose, trehalose, bovine or human serum albumin, citrate, acetate, Ringer's and Hank's solutions, cysteine, arginine, carnitine, alanine, glycine, lysine, valine, leucine, polyvinylpyrrolidone, polyethylene and glycol. Preferably, this formulation is stable for at least six months at 4° C.

In some embodiments, the pharmaceutical composition provided herein comprises a buffer, such as phosphate buffered saline (PBS) or sodium phosphate/sodium sulfate, tris buffer, glycine buffer, sterile water and other buffers known to the ordinarily skilled artisan such as those described by Good et al. (1966) Biochemistry 5:467. The pH of the buffer in which the pharmaceutical composition comprising the tumor suppressor gene contained in the adenoviral vector delivery system, may be in the range of 6.5 to 7.75, preferably 7 to 7.5, and most preferably 7.2 to 7.4.

Methods

As alluded to above, the subject polynucleotide cassettes and gene delivery vectors, referred to collectively herein as the “subject compositions”, find use in expressing a transgene in cone cells of an animal. For example, the subject compositions may be used in research, e.g. to determine the effect that the gene has on cone cell viability and/or function. As another example, the subject compositions may be used in medicine, e.g. to treat a cone cell disorder. Thus, in some aspects of the invention, methods are provided for the expression of a gene in cone cells, the method comprising contacting cone cells with a composition of the present disclosure. In some embodiments, contacting occurs in vitro. In some embodiments, contacting occurs in vivo, i.e., the subject composition is administered to a subject.

For instances in which cone cells are to be contacted in vitro with a subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette, the cells may be from any mammalian species, e.g. rodent (e.g. mice, rats, gerbils, squirrels), rabbit, feline, canine, goat, ovine, pig, equine, bovine, primate, human. Cells may be from established cell lines, e.g. WERI cells, 661W cells, or they may be primary cells, where “primary cells”, “primary cell lines”, and “primary cultures” are used interchangeably herein to refer to cells and cells cultures that have been derived from a subject and allowed to grow in vitro for a limited number of passages, i.e. splittings, of the culture. For example, primary cultures are cultures that may have been passaged 0 times, 1 time, 2 times, 4 times, 5 times, 10 times, or 15 times, but not enough times go through the crisis stage. Typically, the primary cell lines of the present invention are maintained for fewer than 10 passages in vitro.

If the cells are primary cells, they may be harvested from a mammal by any convenient method, e.g. whole explant, biopsy, etc. An appropriate solution may be used for dispersion or suspension of the harvested cells. Such solution will generally be a balanced salt solution, e.g. normal saline, PBS, Hank's balanced salt solution, etc., conveniently supplemented with fetal calf serum or other naturally occurring factors, in conjunction with an acceptable buffer at low concentration, generally from 5-25 mM. Convenient buffers include HEPES, phosphate buffers, lactate buffers, etc. The cells may be used immediately, or they may be stored, frozen, for long periods of time, being thawed and capable of being reused. In such cases, the cells will usually be frozen in 10% DMSO, 50% serum, 40% buffered medium, or some other such solution as is commonly used in the art to preserve cells at such freezing temperatures, and thawed in a manner as commonly known in the art for thawing frozen cultured cells.

To promote expression of the transgene, the subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette will be contacted with the cells for about 30 minutes to 24 hours or more, e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 12 hours, 16 hours, 18 hours, 20 hours, 24 hours, etc. The subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette may be provided to the subject cells one or more times, e.g. one time, twice, three times, or more than three times, and the cells allowed to incubate with the agent(s) for some amount of time following each contacting event e.g. 16-24 hours, after which time the media is replaced with fresh media and the cells are cultured further. Contacting the cells may occur in any culture media and under any culture conditions that promote the survival of the cells. For example, cells may be suspended in any appropriate nutrient medium that is convenient, such as Iscove's modified DMEM or RPMI 1640, supplemented with fetal calf serum or heat inactivated goat serum (about 5-10%), L-glutamine, a thiol, particularly 2-mercaptoethanol, and antibiotics, e.g. penicillin and streptomycin. The culture may contain growth factors to which the cells are responsive. Growth factors, as defined herein, are molecules capable of promoting survival, growth and/or differentiation of cells, either in culture or in the intact tissue, through specific effects on a transmembrane receptor. Growth factors include polypeptides and non-polypeptide factors.

Typically, an effective amount of subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette is provided to produce the expression of the transgene in cells. As discussed elsewhere herein, the effective amount may be readily determined empirically, e.g. by detecting the presence or levels of transgene gene product, by detecting an effect on the viability or function of the cone cells, etc. Typically, an effect amount of subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette will promote greater expression of the transgene in cone cells than the same amount of a polynucleotide cassette as known in the art, e.g. a pR2.1 (nucleotides 1-2274 of SEQ ID NO:50), pR1.7, pR1.5, pR1.1, or IRBP/GNAT2 cassette. Typically, expression will be enhanced 2-fold or more relative to the expression from a reference, or control, polynucleotide cassette e.g. as known in the art, for example 3-fold, 4-fold, or 5-fold or more, in some instances 10-fold, 20-fold or 50-fold or more, e.g. 100-fold.

In some embodiments, as when the transgene is a selectable marker, the population of cells may be enriched for those comprising the subject polynucleotide cassette by separating the modified cells from the remaining population. Separation may be by any convenient separation technique appropriate for the selectable marker used. For example, if the transgene is a fluorescent marker, cells may be separated by fluorescence activated cell sorting, whereas if the transgene is a cell surface marker, cells may be separated from the heterogeneous population by affinity separation techniques, e.g. magnetic separation, affinity chromatography, “panning” with an affinity reagent attached to a solid matrix, or other convenient technique. Techniques providing accurate separation include fluorescence activated cell sorters, which can have varying degrees of sophistication, such as multiple color channels, low angle and obtuse light scattering detecting channels, impedance channels, etc. The cells may be selected against dead cells by employing dyes associated with dead cells (e.g. propidium iodide). Any technique may be employed which is not unduly detrimental to the viability of the cells. Cell compositions that are highly enriched for cells comprising the subject polynucleoties are achieved in this manner. By “highly enriched”, it is meant that the genetically modified cells will be 70% or more, 75% or more, 80% or more, 85% or more, 90% or more of the cell composition, for example, about 95% or more, or 98% or more of the cell composition. In other words, the composition may be a substantially pure composition of genetically modified cells.

For instances in which cone cells are to be contacted in vivo with a subject polynucleotide cassette or gene delivery vector comprising a subject polynucleotide cassette, the subject may be any mammal, e.g. rodent (e.g. mice, rats, gerbils), rabbit, feline, canine, goat, ovine, pig, equine, bovine, or primate. In certain embodiments, the subject is a primate of the Parvorder Catarrhini. As is known in the art, Catarrhini is one of the two subdivisions of the higher primates (the other being the New World monkeys), and includes Old World monkeys and the apes, which in turn are further divided into the lesser apes or gibbons and the great apes, consisting of the orangutans, gorillas, chimpanzees, bonobos, and humans. In a further preferred embodiment, the primate is a human.

The subject composition may be administered to the retina of the subject by any suitable method. For example, the subject composition may be administered intraocularly via intravitreal injection or subretinal injection. The general methods for delivering a vector via intravitreal injection or via subretinal injection may be illustrated by the following brief outlines. These examples are merely meant to illustrate certain features of the methods, and are in no way meant to be limiting.

For subretinal administration, the vector can be delivered in the form of a suspension injected subretinally under direct observation using an operating microscope. Typically, a volume of 1 to 200 uL, e.g. 50 uL, 100 uL, 150 ul, or 200 uL, but usually no more than 200 uL, of the subject composition will be administered by such methods. This procedure may involve vitrectomy followed by injection of vector suspension using a fine cannula through one or more small retinotomies into the subretinal space. Briefly, an infusion cannula can be sutured in place to maintain a normal globe volume by infusion (of e.g. saline) throughout the operation. A vitrectomy is performed using a cannula of appropriate bore size (for example 20 to 27 gauge), wherein the volume of vitreous gel that is removed is replaced by infusion of saline or other isotonic solution from the infusion cannula. The vitrectomy is advantageously performed because (1) the removal of its cortex (the posterior hyaloid membrane) facilitates penetration of the retina by the cannula; (2) its removal and replacement with fluid (e.g. saline) creates space to accommodate the intraocular injection of vector, and (3) its controlled removal reduces the possibility of retinal tears and unplanned retinal detachment.

For intravitreal administration, the vector can be delivered in the form of a suspension. Initially, topical anesthetic is applied to the surface of the eye followed by a topical antiseptic solution. The eye is held open, with or without instrumentation, and the vector is injected through the sclera with a short, narrow, for example a 30 gauge needle, into the vitreous cavity of the eye of a subject under direct observation. Typically, a volume of 1 to 100 uL, e.g. 25 uL, 50 uL, or 100 uL, and usually no more than 100 uL, of the subject composition may be delivered to the eye by intravitreal injection without removing the vitreous. Alternatively, a vitrectomy may be performed, and the entire volume of vitreous gel is replaced by an infusion of the subject composition. In such cases, up to about 4 mL of the subject composition may be delivered, e.g. to a human eye. Intravitreal administration is generally well tolerated. At the conclusion of the procedure, there is sometimes mild redness at the injection site. There is occasional tenderness, but most patients do not report any pain. No eye patch or eye shield is necessary after this procedure, and activities are not restricted. Sometimes, an antibiotic eye drop is prescribed for several days to help prevent infection.

The methods and compositions of the present disclosure find use in the treatment of any condition that can be addressed, at least in part, by gene therapy of cone photoreceptor cells. Thus, the compositions and methods of the present disclosure find use in the treatment of individuals in need of a cone cell therapy. By a person in need of a cone cell therapy, it is meant an individual having or at risk of developing a cone cell disorder. By a “cone cell disorder” it is meant any disorder impacting retinal cone cells, including but not limited to vision disorders of the eye that are associated with a defect within cone cells, i.e. a cone-instrinsic defect, e.g. macular dystrophies such as Stargardt's macular dystrophy, cone dystrophy, cone-rod dystrophy, Spinocerebellar ataxia type 7, and Bardet-Biedl syndrome-1; as well as color vision disorders, including achromatopsia, incomplete achromatopsia, blue cone monochromacy, and protan, deutan, and tritan defects; as well as vision disorders of the central macula (within primates) that may be treated by targeting cone cells, e.g. age-related macular degeneration, macular telangiectasia, retinitis pigmentosa, diabetic retinopathy, retinal vein occlusions, glaucoma, Sorsby's fundus dystrophy, adult vitelliform macular dystrophy, Best's disease, rod-cone dystrophy, Leber's congenital amaurosis, and X-linked retinoschisis.

Stargardt's macular dystrophy. Stargardt's macular dystrophy, also known as Stargardt Disease and fundus flavimaculatus, is an inherited form of juvenile macular degeneration that causes progressive vision loss usually to the point of legal blindness. The onset of symptoms usually appears between the ages of six and thirty years old (average of about 16-18 years). Mutations in several genes, including ABCA4, CNGB3, ELOVL4, PROM1, are associated with the disorder. Symptoms typically develop by twenty years of age, and include wavy vision, blind spots, blurriness, impaired color vision, and difficulty adapting to dim lighting. The main symptom of Stargardt disease is loss of visual acuity, which ranges from 20/50 to 20/200. In addition, those with Stargardt disease are sensitive to glare; overcast days offer some relief. Vision is most noticeably impaired when the macula is damaged, which can be observed by fundus exam.

Cone dystrophy. Cone dystrophy (COD) is an inherited ocular disorder characterized by the loss of cone cells. The most common symptoms of cone dystrophy are vision loss (age of onset ranging from the late teens to the sixties), sensitivity to bright lights, and poor color vision. Visual acuity usually deteriorates gradually, but it can deteriorate rapidly to 20/200; later, in more severe cases, it drops to “counting fingers” vision. Color vision testing using color test plates (HRR series) reveals many errors on both red-green and blue-yellow plates. It is believed that the dystrophy is primary, since subjective and objective abnormalities of cone function are found before ophthalmoscopic changes can be seen. However, the retinal pigment epithelium (RPE) rapidly becomes involved, leading to a retinal dystrophy primarily involving the macula. The fundus exam via ophthalmoscope is essentially normal early on in cone dystrophy, and definite macular changes usually occur well after visual loss. The most common type of macular lesion seen during ophthalmoscopic examination has a bull's-eye appearance and consists of a doughnut-like zone of atrophic pigment epithelium surrounding a central darker area. In another, less frequent form of cone dystrophy there is rather diffuse atrophy of the posterior pole with spotty pigment clumping in the macular area. Rarely, atrophy of the choriocapillaris and larger choroidal vessels is seen in patients at an early stage. Fluorescein angiography (FA) is a useful adjunct in the workup of someone suspected to have cone dystrophy, as it may detect early changes in the retina that are too subtle to be seen by ophthalmoscope. Because of the wide spectrum of fundus changes and the difficulty in making the diagnosis in the early stages, electroretinography (ERG) remains the best test for making the diagnosis. Abnormal cone function on the ERG is indicated by a reduced single-flash and flicker response when the test is carried out in a well-lit room (photopic ERG). Mutations in several genes, including GUCA1A, PDE6C, PDE6H, and RPGR, are associated with the disorder.

Cone-rod dystrophy. Cone-rod dystrophy (CRD, or CORD) is an inherited retinal dystrophy that belongs to the group of pigmentary retinopathies. CRD is characterized by retinal pigment deposits visible on fundus examination, predominantly localized to the macular region and the loss of both cone and rod cells. In contrast to rod-cone dystrophy (RCD) resulting from the primary loss in rod photoreceptors and later followed by the secondary loss in cone photoreceptors, CRD reflects the opposite sequence of events: primary cone involvement, or, sometimes, by concomitant loss of both cones and rods. Symptoms include decreased visual acuity, color vision defects, photoaversion and decreased sensitivity in the central visual field, later followed by progressive loss in peripheral vision and night blindness. Mutations in several genes, including ADAM9, PCDH21, CRX, GUCY2D, PITPNM3, PROM1, PRPH2, RAX2, RIMS1, RPGR, and RPGRIP1, are associated with the disorder.

Spinocerebellar ataxia type 7. Spinocerebellar ataxia is a progressive, degenerative, inherited disease characterized by slowly progressive incoordination of gait and is often associated with poor coordination of hands, speech, and eye movements. There are multiple types of SCA, with Spinocerebellar ataxia type 7 (SCA-7) differing from most other SCAs in that visual problems can occur in addition to poor coordination. SCA-7 is associated with automosmal dominant mutations in the ATXN7/SCA7 gene. When the disease manifests itself before age 40, visual problems rather than poor coordination are typically the earliest signs of disease. Early symptoms include difficulty distinguishing colors and decreased central vison. In addition, symptoms of ataxia (incoordination, slow eye movements, and mild changes in sensation or reflexes) may be detectable. Loss of motor control, unclear speech, and difficulty swallowing become prominent as the disease progresses.

Bardet-Biedl syndrome-1. Bardet-Biedl syndrome-1 (BBS-1) is a pleiotropic disorder with variable expressivity and a wide range of clinical variability observed both within and between families. The main clinical features are rod-cone dystrophy, with childhood-onset visual loss preceded by night blindness; postaxial polydactyly; truncal obesity that manifests during infancy and remains problematic throughout adulthood; specific learning difficulties in some but not all individuals; male hypogenitalism and complex female genitourinary malformations; and renal dysfunction, a major cause of morbidity and mortality. Vision loss is one of the major features of Bardet-Biedl syndrome. Problems with night vision become apparent by mid-childhood, followed by blind spots that develop in the peripheral vision. Over time, these blind spots enlarge and merge to produce tunnel vision. Most people with Bardet-Biedl syndrome also develop blurred central vision (poor visual acuity) and become legally blind by adolescence or early adulthood. Bardet-Biedl syndrome can result from mutations in at least 14 different genes (often called BBS genes) known or suspected to play critical roles in cilia function, with mutations in BBS1 and BBS10 being the most common.

Achromatopsia. Achromatopsia, or Rod monochromatism, is a disorder in which subjects experience a complete lack of the perception of color, such that the subject sees only in black, white, and shades of grey. Other symptoms include reduced visual acuity, photophobia, nystagmus, small central scotoma, and eccentric fixation. The disorder is frequently noticed first in children around six months of age by their photophobic activity and/or their nystagmus. Visual acuity and stability of the eye motions generally improve during the first 6-7 years of life (but remain near 20/200). Mutations in CNGB3, CNGA3, GNAT2, PDE6C, and PDE6HI have been associated with the disorder.

Incomplete achromatopsia. Incomplete achromatopsia is similar to Achromatopsia but with less penetrance. In incomplete achromatopsia, the symptoms are similar to those of complete achromatopsia except in a diminished form. Individuals with incomplete achromatopsia have reduced visual acuity with or without nystagmus or photophobia. Furthermore, these individuals show only partial impairment of cone cell function but again have retained rod cell function.

Blue cone monochromacy. Blue cone (S cone) monochromatism (BCM) is a rare X-linked congenital stationary cone dysfunction syndrome, affecting approximately 1 in 100,000 individuals. Affected males with BCM have no functional long wavelength sensitive (L) or medium wavelength sensitive (M) cones in the retina, due to mutations at the genetic locus for the L and M-opsin genes. Color discrimination is severely impaired from birth, and vision is derived from the remaining preserved S cones and rod photoreceptors. BCM typically presents with reduced visual acuity (6/24 to 6/60), pendular nystagmus, photophobia, and patients often have myopia. The rod-specific and maximal electroretinogram (ERG) usually show no definite abnormality, whereas the 30 Hz cone ERG cannot be detected. Single flash photopic ERG is often recordable, albeit small and late, and the S cone ERG is well preserved.

Color vision deficiency. Color vision deficiency (CVD), or color blindness, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Individuals suffering from color blindness may be identified as such using any of a number of color vision tests, e.g., color ERG (cERG), pseudoisochromatic plates (Ishihara plates, Hardy-Rand-Ritter polychromatic plates), the Farnsworth-Munsell 100 hue test, the Farnsworth's panel D-15, the City University test, Kollner's rule, etc. Examples of color vision deficiencies include protan defects, deutan defects, and tritan defects. Protan defects include protanopia (an insensitivity to red light) and protanomaly (a reduced sensitivity to red light), and are associated with mutations in the L-Opsin gene (OPN1LW). Deutan defects include deuteranopia (an insensitivity to green light) and deutanomaly (a reduced sensitivity to green light), and are associated with mutations in the M-Opsin gene (OPN1MW). Tritan defects include tritanopia (an insensitivity to blue light) and tritanomaly (a reduced sensitivity to blue light), and are associated with mutations in the S-Opsin gene (OPN1SW).

Age-related macular degeneration. Age-related macular degeneration (AMD) is one of the leading causes of vision loss in people over the age of 50 years. AMD mainly affects central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. The vision loss in this condition results from a gradual deterioration of photoreceptors in the macula. Side (peripheral) vision and night vision are generally not affected.

Researchers have described two major types of age-related macular degeneration, known as the dry, or “nonexudative” form, and the wet, or “exudative” or “neovascular”, form, both of which may be treated by delivering transgenes in the context of the subject polynucleotide cassettes.

Dry AMD is characterized by a buildup of yellow deposits called drusen between the retinal pigment epithelium and the underlying choroid of the macula, which may be observed by Fundus photography. This results in a slowly progressive loss of vision. The condition typically affects vision in both eyes, although vision loss often occurs in one eye before the other. Other changes may include pigment changes and RPE atrophy. For example, in certain cases called central geographic atrophy, or “GA”, atrophy of the retinal pigment epithelial and subsequent loss of photoreceptors in the central part of the eye is observed. Dry AMD has been associated with mutations in CD59 and genes in the complement cascade.

Wet AMD is a progressed state of dry AMD, and occurs in abut 10% of dry AMD patients. Pathological changes include retinal pigment epithelial cells (RPE) dysfunction, fluid collecting under the RPE, and choroidal neovascularization (CNV) in the macular area. Fluid leakage, RPE or neural retinal detachment and bleeding from ruptured blood vessels can occur in severe cases. Symptoms of wet AMD may include visual distortions, such as straight lines appearing wavy or crooked, a doorway or street sign looking lopsided, or objects appearing smaller or farther away than they really are; decreased central vision; decreased intensity or brightness of colors; and well-defined blurry spot or blind spot in the field of vision. Onset may be abrupt and worsen rapidly. Diagnosis may include the use of an Amsler grid to test for defects in the subject's central vision (macular degeneration may cause the straight lines in the grid to appear faded, broken or distorted), fluorescein angiogram to observe blood vessel or retinal abnormalities, and optical coherence tomography to detect retina swelling or leaking blood vessels. A number of cellular factors have been implicated in the generation of CNV, among which are vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), pigment epithelium-derived factor (PEDF), hypoxia inducible factor (HIF), angiopoietin (Ang), and other cytokines, mitogen-activated protein kinases (MAPK) and others.

Macular telangiectasia. Macular telangiectasia (MacTel) is a form of pathologically dilated blood vessels (telangiectasia) in the parafoveal region of the macula. The tissue deteriorates and the retinal structure becomes scarred due to the development of liquid-filled cysts, which impairs nutrition of the photoreceptor cells and destroys vision permanently. There are two types of MacTel, type 1 and type 2. Macular telangiectasia type 2 is a bilateral disease, whose prevalence has recently been shown to be as high as 0.1% in persons 40 years and older. Biomicroscopy may show reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy, and neovascular complexes. Fluorescein angiography shows telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. High-resolution optical coherence tomography (OCT) may reveal disruption of the photoreceptor inner segment-outer segment border, hyporeflective cavities at the level of the inner or outer retina, and atrophy of the retina in later stages. In Type 1 macular telangiectasia, the disease almost always occurs in one eye, which differentiates it from Type 2. While MacTel does not usually cause total blindness, it commonly causes loss of the central vision, which is required for reading and driving vision, over a period of 10-20 years.

Retinitis pigmentosa. Retinitis Pigmentosa (RP) is a group of inherited disorders characterized by progressive peripheral vision loss and night vision difficulties (nyctalopia) that can lead to central vision loss. Presenting signs and symptoms of RP vary, but the classic ones include nyctalopia (night blindness, most commonly the earliest symptom in RP); visual loss (usually peripheral, but in advanced cases, central visual loss); and photopsia (seeing flashes of light). Because RP is a collection of many inherited diseases, significant variability exists in the physical findings. Ocular examination involves assessment of visual acuity and pupillary reaction, as well as anterior segment, retinal, and funduscopic evaluation. In some instances, the RP is one aspect of a syndrome, e.g. syndromes that are also associated with hearing loss (Usher syndrome, Waardenburg syndrome, Alport syndrome, Refsum disease); Kearns-Sayre syndrome (external ophthalmoplegia, lid ptosis, heart block, and pigmentary retinopathy); Abetalipoproteinemia (Fat malabsorption, fat-soluble vitamin deficiencies, spinocerebellar degeneration, and pigmentary retinal degeneration); mucopolysaccharidoses (eg, Hurler syndrome, Scheie syndrome, Sanfilippo syndrome); Bardet-Biedl syndrome (Polydactyly, truncal obesity, kidney dysfunction, short stature, and pigmentary retinopathy); and neuronal ceroid lipofuscinosis (Dementia, seizures, and pigmentary retinopathy; infantile form is known as Jansky-Bielschowsky disease, juvenile form is Vogt-Spielmeyer-Batten disease, and adult form is Kufs syndrome). Retinitis pigmentosa is most commonly associated with mutations in the RHO, RP2, RPGR, RPGRIP1, PDE6A, PDE6B, MERTK, PRPH2, CNGB1, USH2A, ABCA4, BBS genes.

Diabetic retinopathy. Diabetic retinopathy (DR) is damage to the retina caused by complications of diabetes, which can eventually lead to blindness. Without wishing to be bound by theory, it is believed that hyperglycemia-induced intramural pericyte death and thickening of the basement membrane lead to incompetence of the vascular walls. These damages change the formation of the blood-retinal barrier and also make the retinal blood vessels become more permeable.

There are two stages of diabetic retinopathy: non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR). Nonproliferative diabetic retinopathy is the first stage of diabetic retinopathy, and is diagnosed by fundoscopic exam and coexistent diabetes. In cases of reduced vision, fluorescein angiography may be done to visualize the vessles in the back of the eye to and any retinal ischemia that may be present. All people with diabetes are at risk for developing NPDR, and as such, would be candidates for prophylactic treatment with the subject vectors. Proliferative diabetic retinopathy is the second stage of diabetic retinopathy, characterized by neovascularization of the retina, vitreous hemorrhage, and blurred vision. In some instances, fibrovascular proliferation causes tractional retinal detachment. In some instances, the vessels can also grow into the angle of the anterior chamber of the eye and cause neovascular glaucoma. Individuals with NPDR are at increased risk for developing PDR, and as such, would be candidates for prophylactic treatment with the subject vectors.

Diabetic macular edema. Diabetic macular edema (DME) is an advanced, vision-limiting complication of diabetic retinopathy that affects nearly 30% of patients who have had diabetes for at least 20 years, and is responsible for much of the vision loss due to DR. It results from retinal microvascular changes that compromise the blood-retinal barrier, causing leakage of plasma constituents into the surrounding retina and, consequently, retinal edema. Without wishing to be bound by theory, it is believed that hyperglycemia, sustained alterations in cell signaling pathways, and chronic microvascular inflammation with leukocyte-mediated injury leads to chronic retinal microvascular damage, which triggers an increase in intraocular levels of VEGF, which in turn increases the permeability of the vasculature.

Patients at risk for developing DME include those who have had diabetes for an extended amount of time and who experience one or more of severe hypertension (high blood pressure), fluid retention, hypoalbuminemia, or hyperlipidemia. Common symptoms of DME are blurry vision, floaters, double vision, and eventually blindness if the condition is allowed to progress untreated. DME is diagnosed by funduscopic examination as retinal thickening within 2 disc diameters of the center of the macula. Other methods that may be employed include Optical coherence tomography (OCT) to detect retinal swelling, cystoid edema, and serous retinal detachment; fluorescein angiography, which distinguishes and localizes areas of focal versus diffuse leakage, thereby guiding the placement of laser photocoagulation if laser photocoagulation is to be used to treat the edema; and color stereo fundus photographs, which can be used to evaluate long-term changes in the retina. Visual acuity may also be measured, especially to follow the progression of macular edema and observe its treatment following administration of the subject pharmaceutical compositions.

Retinal vein occlusions. A retinal vein occlusion (RVO) is a blockage of the portion of the circulation that drains the retina of blood. The blockage can cause back-up pressure in the capillaries, which can lead to hemorrhages and also to leakage of fluid and other constituents of blood.

Glaucoma. Glaucoma is a term describing a group of ocular (eye) disorders that result in optic nerve damage, often associated with increased fluid pressure in the eye (intraocular pressure)(IOP). The disorders can be roughly divided into two main categories, “open-angle” and “closed-angle” (or “angle closure”) glaucoma. Open-angle glaucoma accounts for 90% of glaucoma cases in the United States. It is painless and does not have acute attacks. The only signs are gradually progressive visual field loss, and optic nerve changes (increased cup-to-disc ratio on fundoscopic examination). Closed-angle glaucoma accounts for less than 10% of glaucoma cases in the United States, but as many as half of glaucoma cases in other nations (particularly Asian countries). About 10% of patients with closed angles present with acute angle closure crises characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure (>30 mmHg), nausea and vomiting, suddenly decreased vision, and a fixed, mid-dilated pupil. It is also associated with an oval pupil in some cases. Modulating the activity of proteins encoded by DLK, NMDA, INOS, CASP-3, Bcl-2, or Bcl-xl may treat the condition.

Sorsby's fundus dystrophy. Sorsby's fundus dystrophy is an autosomal dominant, retinal disease associated with mutations in the TIMP3 gene. Clinically, early, mid-peripheral, drusen and colour vision deficits are found. Some patients complain of night blindness. Most commonly, the presenting symptom is sudden acuity loss, manifest in the third to fourth decades of life, due to untreatable submacular neovascularisation. Histologically, there is accumulation of a confluent lipid containing material 30 μm thick at the level of Bruch's membrane.

Vitelliform macular dystrophy. Vitelliform macular dystrophy is a genetic eye disorder that can cause progressive vision loss. Vitelliform macular dystrophy is associated with the buildup of fatty yellow pigment (lipofuscin) in cells underlying the macula. Over time, the abnormal accumulation of this substance can damage cells that are critical for clear central vision. As a result, people with this disorder often lose their central vision, and their eyesight may become blurry or distorted. Vitelliform macular dystrophy typically does not affect side (peripheral) vision or the ability to see at night.

Researchers have described two forms of vitelliform macular dystrophy with similar features. The early-onset form (known as Best disease) usually appears in childhood; the onset of symptoms and the severity of vision loss vary widely. It is associated with mutations in the VMD2/BEST1 gene. The adult-onset form (Adult vitelliform macular dystrophy) begins later, usually in mid-adulthood, and tends to cause vision loss that worsens slowly over time. It has been associated with mutations in the PRPH2 gene. The two forms of vitelliform macular dystrophy each have characteristic changes in the macula that can be detected during an eye examination.

Rod-cone dystrophy. Rod-cone dystrophies are a family of progressive diseases in which rod dysfunction, which leads to night blindness and loss of peripheral visual field expanses, is either the prevailing problem or occurring at least as severely as cone dysfunction. A scallop-bordered lacunar atrophy may be seen in the midperiphery of the retina. The macula is only mildly involved by clinical examination although central retinal thinning is seen in all cases. Dyschromatopsia is mild early and usually becomes more severe. The visual fields are moderately to severely constricted although in younger individuals a typical ring scotoma is present. The peripheral retina contains ‘white dots’ and often resembles the retinal changes seen in retinitis punctate albescens. Retinitis pigmentosa is the main group of diseases included under this definition and, as a whole, is estimated to affect approximately one in every 3,500 people. Depending on the classification criteria used, about 60-80% of all retinitis pigmentosa patients have a clear-cut rod-cone dystrophy pattern of retinal disease and once other syndromic forms are taken into account, about 50-60% of all retinitis pigmentosas fall in the rod-cone dystrophy nonsyndromic category.

Leber's congenital amaurosis. Leber's congenital amaurosis (LCA) is a severe dystrophy of the retina that typically becomes evident in the first year of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia, and keratoconus. Visual acuity is rarely better than 20/400. A characteristic finding is Franceschetti's oculo-digital sign, comprising eye poking, pressing, and rubbing. The appearance of the fundus is extremely variable. While the retina may initially appear normal, a pigmentary retinopathy reminiscent of retinitis pigmentosa is frequently observed later in childhood. The electroretinogram (ERG) is characteristically “nondetectable” or severely subnormal. Mutations in 17 genes are known to cause LCA: GUCY2D (locus name: LCA1), RPE65 (LCA2), SPATA7 (LCA3), AIPL1 (LCA4), LCA5 (LCA5), RPGRIP1 (LCA6), CRX (LCAT), CRB1 (LCA5), NMNAT1 (LCA5), CEP290 (LCA10), IMPDH1 (LCA11), RD3 (LCA12), RDH12 (LCA13), LRAT (LCA14), TULP1 (LCA15), KCNJ13 (LCA16), and IQCB1. Together, mutations in these genes are estimated to account for over half of all LCA diagnoses. At least one other disease locus for LCA has been reported, but the gene is not known.

X-linked retinoschisis. X-linked retinoschisis (XLRS) is characterized by symmetric bilateral macular involvement with onset in the first decade of life, in some cases as early as age three months. Fundus examination shows areas of schisis (splitting of the nerve fiber layer of the retina) in the macula, sometimes giving the impression of a spoke wheel pattern. Schisis of the peripheral retina, predominantly inferotemporally, occurs in approximately 50% of individuals. Affected males typically have vision of 20/60 to 20/120. Visual acuity often deteriorates during the first and second decades of life but then remains relatively stable until the fifth or sixth decade. The diagnosis of X-linked juvenile retinoschisis is based on fundus findings, results of electrophysiologic testing, and molecular genetic testing. RS1 is the only gene known to be associated with X-linked juvenile retinoschisis.

An individual affected by a cone cell disorder or at risk for developing a cone cell disorder can be readily identified using techniques to detect the symptoms of the disorder as known in the art, including, without limitation, fundus photography; Optical coherence tomography (OCT); adaptive optics (AO); electroretinography, e.g. ERG, color ERG (cERG); color vision tests such as pseudoisochromatic plates (Ishihara plates, Hardy-Rand-Ritter polychromatic plates), the Farnsworth-Munsell 100 hue test, the Farnsworth's panel D-15, the City university test, Kollner's rule, and the like; and visual acuity tests such as the ETDRS letters test, Snellen visual acuity test, visual field test, contrast sensitivity test, and the like; as will be known by the ordinarily skilled artisan. Additionally or alternatively, the individual affected by a cone cell disorder or at risk for developing a cone cell disorder can be readily identified using techniques to detect gene mutations that are associated with the cone cell disorder as known in the art, including, without limitation, PCR, DNA sequence analysis, restriction digestion, Southern blot hybridization, mass spectrometry, etc. In some embodiments, the method comprises the step of identifying the individual in need of a cone cell therapy. In such instances, any convenient method for determining if the individual has the symptom(s) of a cone cell disorder or is at risk for developing a cone cell disorder, for example by detecting the symptoms described herein or known in the art, by detecting a mutation in a gene as herein or as known in the art, etc. may be utilized to identify the individual in need of a cone cell therapy.

In practicing the subject methods, the subject composition is typically delivered to the retina of the subject in an amount that is effective to result in the expression of the transgene in the cone cells. In some embodiments, the method comprises the step of detecting the expression of the transgene in the cone cells.

There are a number of ways to detect the expression of a transgene, any of which may be used in the subject embodiments. For example, expression may be detected directly, i.e. by measuring the amount of gene product, for example, at the RNA level, e.g. by RT-PCR, Northern blot, RNAse protection; or at the protein level, e.g. by Western blot, ELISA, immunohistochemistry, and the like. As another example, expression may be detected indirectly, i.e. by detecting the impact of the gene product on the viability or function of the cone photoreceptor in the subject. For example, if the gene product encoded by the transgene improves the viability of the cone cell, the expression of the transgene may be detected by detecting an improvement in viability of the cone cell, e.g. by fundus photography, Optical coherence tomography (OCT), Adaptive Optics (AO), and the like. If the gene product encoded by the transgene alters the activity of the cone cell, the expression of the transgene may be detected by detecting a change in the activity of the cone cell, e.g. by electroretinogram (ERG) and color ERG (cERG); functional adaptive optics; color vision tests such as pseudoisochromatic plates (Ishihara plates, Hardy-Rand-Ritter polychromatic plates), the Farnsworth-Munsell 100 hue test, the Farnsworth's panel D-15, the City university test, Kollner's rule, and the like; and visual acuity tests such as the ETDRS letters test, Snellen visual acuity test, visual field test, contrast sensitivity test, and the like, as a way of detecting the presence of the delivered polynucleotide. In some instances, both an improvement in viability and a modification in cone cell function may be detected.

In some embodiments, the subject method results in a therapeutic benefit, e.g. preventing the development of a disorder, halting the progression of a disorder, reversing the progression of a disorder, etc. In some embodiments, the subject method comprises the step of detecting that a therapeutic benefit has been achieved. The ordinarily skilled artisan will appreciate that such measures of therapeutic efficacy will be applicable to the particular disease being modified, and will recognize the appropriate detection methods to use to measure therapeutic efficacy. For example, therapeutic efficacy in treating macular degeneration may be observed as a reduction in the rate of macular degeneration or a cessation of the progression of macular degeneration, effects which may be observed by, e.g., fundus photography, OCT, or AO, by comparing test results after administration of the subject composition to test results before administration of the subject composition. As another example, therapeutic efficacy in treating a progressive cone dysfunction may be observed as a reduction in the rate of progression of cone dysfunction, as a cessation in the progression of cone dysfunction, or as an improvement in cone function, effects which may be observed by, e.g., ERG and/or cERG; color vision tests; functional adaptive optics; and/or visual acuity tests, for example, by comparing test results after administration of the subject composition to test results before administration of the subject composition and detecting a change in cone viability and/or function. As a third example, therapeutic efficacy in treating a color vision deficiency may be observed as an alteration in the individual's perception of color, e.g. in the perception of red wavelengths, in the perception of green wavelengths, in the perception of blue wavelengths, effects which may be observed by, e.g., cERG and color vision tests, for example, by comparing test results after administration of the subject composition to test results before administration of the subject composition and detecting a change in cone viability and/or function.

Expression of the transgene using the subject transgene is expected to be robust. Accordingly, in some instances, the expression of the transgene, e.g. as detected by measuring levels of gene product, by measuring therapeutic efficacy, et.c, may be observed two months or less after administration, e.g. 4, 3 or 2 weeks or less after administration, for example, 1 week after administration of the subject composition. Expression of the transgene is also expected to persist over time. Accordingly, in some instances, the expression of the transgene, e.g. as detected by measuring levels of gene product, by measuring therapeutic efficacy, etc., may be observed 2 months or more after administration of the subject composition, e.g., 4, 6, 8, or 10 months or more, in some instances 1 year or more, for example 2, 3, 4, or 5 years, in certain instances, more than 5 years.

In certain embodiments, the method comprises the step of detecting expression of the transgene in the cone cells, wherein expression is enhanced relative to expression from a polynucleotide cassette not comprising the one or more improved elements of the present disclosure, i.e. a reference control, e.g. the pR2.1 promoter or variants thereof (e.g. pR1.7, pR1.5, pR1.1, etc.) as disclosed in, e.g., US Application No. 2013/0317091, or the synthetic IRBP/GNAT2 promoter as disclosed in US Application No. 2014/0275231; the full disclosures of which are incorporated herein by reference. Typically, expression will be enhanced 2-fold or more relative to the expression from a reference, i.e. a control polynucleotide cassette, e.g. as known in the art, for example 3-fold, 4-fold, or 5-fold or more, in some instances 10-fold, 20-fold or 50-fold or more, e.g. 100-fold, as evidenced by, e.g. earlier detection, higher levels of gene product, a stronger functional impact on the cells, etc.

Typically, if the subject composition is an rAAV comprising the subject a polynucleotide cassette of the present disclosure, an effective amount to achieve a change in will be about 1×10⁸ vector genomes or more, in some cases 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², or 1×10¹³ vector genomes or more, in certain instances, 1×10¹⁴ vector genomes or more, and usually no more than 1×10¹⁵ vector genomes. In some cases, the amount of vector genomes that is delivered is at most about 1×10¹⁵ vector genomes, e.g. 1×10¹⁴ vector genomes or less, for example 1×10¹³, 1×10¹², 1×10¹¹, 1×10¹⁰, or 1×10⁹ vector genomes or less, in certain instances 1×10⁸ vector genomes, and typically no less than 1×10⁸ vector genomes. In some cases, the amount of vector genomes that is delivered is 1×10¹⁰ to 1×10¹¹ vector genomes. In some cases, the amount of vector genomes that is delivered is 1×10¹⁰ to 3×10¹² vector genomes. In some cases, the amount of vector genomes that is delivered is 1×10⁹ to 3×10¹³ vector genomes. In some cases, the amount of vector genomes that is delivered is 1×10⁸ to 3×10¹⁴ vector genomes.

In some cases, the amount of pharmaceutical composition to be administered may be measured using multiplicity of infection (MOI). In some cases, MOI may refer to the ratio, or multiple of vector or viral genomes to the cells to which the nucleic may be delivered. In some cases, the MOI may be 1×10⁶. In some cases, the MOI may be 1×10⁵-1×10⁷. In some cases, the MOI may be 1×10⁴-1×10⁸. In some cases, recombinant viruses of the disclosure are at least about 1×10¹, 1×10², 1×10³, 1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸, 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², 1×10¹³, 1×10¹⁴, 1×10¹⁵, 1×10¹⁶, 1×10¹⁷, and 1×10¹⁸ MOI. In some cases, recombinant viruses of this disclosure are 1×10⁸ to 3×10¹⁴ MOI. In some cases, recombinant viruses of the disclosure are at most about 1×10¹, 1×10², 1×10³, 1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸, 1×10⁹, 1×10¹⁰, 1×10¹¹, 1×10¹², 1×10¹³, 1×10¹⁴, 1×10¹⁵, 1×10¹⁶, 1×10¹⁷ and 1×10¹⁸ MOI.

In some aspects, the amount of pharmaceutical composition comprises about 1×10⁸ to about 1×10¹⁵ particles of recombinant viruses, about 1×10⁹ to about 1×10¹⁴ particles of recombinant viruses, about 1×10¹⁰ to about 1×10¹³ particles of recombinant viruses, or about 1×10¹¹ to about 3×10¹² particles of recombinant viruses.

Individual doses are typically not less than an amount required to produce a measurable effect on the subject, and may be determined based on the pharmacokinetics and pharmacology for absorption, distribution, metabolism, and excretion (“ADME”) of the subject composition or its by-products, and thus based on the disposition of the composition within the subject. This includes consideration of the route of administration as well as dosage amount, which can be adjusted for subretinal (applied directly to where action is desired for mainly a local effect), intravitreal (applied to the vitreaous for a pan-retinal effect), or parenteral (applied by systemic routes, e.g. intravenous, intramuscular, etc.) applications. Effective amounts of dose and/or dose regimen can readily be determined empirically from preclinical assays, from safety and escalation and dose range trials, individual clinician-patient relationships, as well as in vitro and in vivo assays such as those described herein and illustrated in the Experimental section, below.

All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.

From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

EXAMPLES

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present invention, and are not intended to limit the scope of what the inventors regard as their invention nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.

General methods in molecular and cellular biochemistry can be found in such standard textbooks as Molecular Cloning: A Laboratory Manual, 3rd Ed. (Sambrook et al., HaRBor Laboratory Press 2001); Short Protocols in Molecular Biology, 4th Ed. (Ausubel et al. eds., John Wiley & Sons 1999); Protein Methods (Bollag et al., John Wiley & Sons 1996); Nonviral Vectors for Gene Therapy (Wagner et al. eds., Academic Press 1999); Viral Vectors (Kaplift & Loewy eds., Academic Press 1995); Immunology Methods Manual (I. Lefkovits ed., Academic Press 1997); and Cell and Tissue Culture: Laboratory Procedures in Biotechnology (Doyle & Griffiths, John Wiley & Sons 1998), the disclosures of which are incorporated herein by reference. Reagents, cloning vectors, and kits for genetic manipulation referred to in this disclosure are available from commercial vendors such as BioRad, Stratagene, Invitrogen, Sigma-Aldrich, and ClonTech.

Background

New therapies are needed for the treatment of many cone photoreceptor associated disorders, including macular dystrophies such as cone-rod dystrophy, cone dystrophy, Stargardt macular dystrophy, and achromatopsia; color vision disorders such as protan, deutan, and tritan defects; and vision disorders of the central macula such as age-related macular degeneration, macular telangiectasia, retinitis pigmentosa, diabetic retinopathy, retinal vein occlusions, glaucoma, Sorsby's fundus dystrophy, adult vitelliform macular dystrophy, Best's disease, and X-linked retinoschisis. As these vision disorders are associated with a loss of function and/or viability of the cone photoreceptors, it is hypothesized that these disorders may be treatable by delivering a therapeutic gene to cone photoreceptors to rescue cone viability and function.

To that end, the polynucleotide cassette “pMNTC” was designed in which enhancer, promoter, 5′UTR, intron, Kozak, and polyadenylation sequences were designed for cone-specific expression (FIG. 10a ). The cassette included an LCR enhancer sequence from the L- and M-opsin genomic locus and a truncated promoter sequence from the M-Opsin gene, comprising about 140 nucleotides upstream of the transcriptional start site. In addition, the cassette included a 5′ untranslated region (5′ UTR) based on the M-opsin 5′UTR but modified to have minimal secondary structure (see FIG. 3) and to include additional sequence at its 3′ end into which an intron was inserted. The intronic sequence used was a pSI chimeric intron having the 5′-donor site from the first intron of the human β-globin gene and the branch and 3′-acceptor site from the intron that lies between the leader and the body of an immunoglobulin gene heavy chain variable region (Bothwell, A. L. et al. (1981) Heavy chain variable region contribution to the NPb family of antibodies: Somatic mutation evident in a gamma 2a variable region. Cell 24, 625-37). The sequences of the donor and acceptor sites, along with the branchpoint site, were changed to match the consensus sequences for splicing (Senapathy, P., Shapiro, M. B. and Harris, N. L. (1990) Meth. Enzymol. 183, 252-78). Also included in the pMNTC polynucleotide cassette was a strong Kozak sequence and an SV40 polyadenylation sequence.

Experiments were also performed to identify the best AAV with which to deliver transgenes to cone cells. Successful delivery of polynucleotides to cells of the retina for the purposes of gene therapy has been achieved using viral vectors such as AAV and lentivirus. However, these viruses must be injected subretinally to reach the cells of the non-human primate (NHP) retina, a procedure that carries with it the risk of retinal damage. A less disruptive approach is administration by intravitreal injection. However, efficient transduction of cone photoreceptors following intravitreal delivery of AAV or lentivirus has never been demonstrated: while reports exist of AAVs with the ability to transduce retinal cone cells with high efficiency (Merigan et al. IOVS 2008, 49 E-abstract 4514), later reports have questioned the efficacy of these vectors (Yin et al. IOVS 2011, 52(5):2775-2783).

Results

Directed evolution of AAV2 has led to the identification of the viral variant “7m8” that is able to transduce photoreceptors better than wild type AAV2 (Dalkara et al. Sci Transl Med 2013). However, the retina contains two types of photoreceptors—rods and cones—and no reports exist demonstrated whether AAV2-7m8 can transduce cone photoreceptors, per se, and more particularly, cone photoreceptors in the highly cone-enriched area of the fovea. To test this possibility, we delivered AAV2-7m8 carrying an expression cassette of the ubiquitous promoter CMV operably linked to GFP to the retina of African Green monkey by intravitreal injection. Intravitreally delivered AAV2-7m8.CMV.GFP appeared to transduce retinal cells in the fovea centralis (the 0.35 mm diameter rod-free region of retina at the center of the foveal pit) and parafovea (the lip of the depression) of primates more efficiently than intravitreally-delivered AAV2 or other AAV variants previously shown in the art to transduce retinal cells. Neither AAV2-7m8 nor the other AAVs tested tested appeared to be able to transduce the cones of the primate fovea, the 1.5 mm-diameter cone-enriched region of retina that surrounds the foveola and forms the slopes of the pit (FIG. 5).

We next packaged a genome comprising pMNTC operably linked to GFP within the AAV2-7m8 capsid, and assessed the ability of this vector composition to express the GFP transgene in cone cells in vivo when injected intravitreally. Expression was evaluated in a number of species with varying numbers of retinal cones cells among total photoreceptors, including mouse (3% cones), rat (1% cones), gerbil (13% cones), and nonhuman primate (5% cones). Contrary to our results in FIG. 5, strong gene expression could be detected throughout the nonhuman primate fovea (FIG. 6). These data indicate that intravitreally delivered AAV2-7m8 can, in fact, transduce retinal cones, and that pMNTC acts as a robust expression cassette in cone cells. Robust reporter gene expression was also seen in the intravireally injected retina of the rat (data not shown) and gerbil (FIG. 8A), with expression levels and anatomic location correlating with cone abundance and location in all species.

To determine the cell-specificity of pMNTC-directed expression, whole mounts of transduced mouse retina were analyzed by immunohistochemistry using an antibody that is specific for cone L and M opsins. The expression of L/M opsin, which labels the outer segments of cone photoreceptors only, was observed in virtually all of the cones of the mouse retina that expressed GFP from the AAV2-7m8.MNTC.GFP vector (FIG. 7), indicating that MNTC-directed expression of transgenes is highly cone-specific. Moreover 80% or more of the cone outer segments that were labelled by the L/M opsin-specific antibody also expressed the GFP transgene, indicating that AAV2-7m8 transduces cones highly efficiently (FIG. 7).

We next compared the ability of pMNTC to promote expression in cone cells to that of pR2.1. pR2.1 comprises the human L/M opsin enhancer (“LCR”) and the promoter region from the human L-Opsin gene. In addition, pR2.1 comprises the L-Opsin 5′UTR fused to additional 5′UTR sequence at its 3′ end, into which modified SV40 late 16s intronic sequence has been inserted. This is followed by the L-Opsin Kozak sequence, which is then typically linked in-frame to a transgene. At the end of the cassette is an SV40 polyA tail.

Viral preparations of AAV2-7m8.MNTC.GFP and AAV2-7m8.pR2.1.GFP were delivered intravitreally to the retinas of gerbils and nonhuman primates in vivo, and the retinas imaged in vivo 2 weeks, 4 weeks, 8 weeks, and 12 weeks later by fundus autofluorescence and OCT. GFP reporter expression was detected sooner, more strongly, and in more cones in gerbil retina transduced with rAAV carrying the pMNTC.GFP expression cassette than in gerbil retinas carrying the pR2.1.GFP expression cassette (FIG. 8B). Likewise, GFP reporter expression was detected sooner and in more cones in nonhuman primate retinas transduced with rAAV carrying the pMNTC.GFP expression cassette as compared to NHP retinas transduced with the pR2.1 expression cassette (FIG. 9, n=4 eyes). In both gerbils and NHP, GFP was consistently observed to be stronger from pMNTC than from pR2.1 throughout the duration of the study.

To determine the contribution of each of the elements in the pMNTC expression cassette to the overall improvement in expression, a series of expression constructs were cloned in which each of the elements in pMNTC was substituted one-by-one with the corresponding element from the pR2.1 expression cassette. These constructs were then packaged into AAV2-7m8 and delivered by intravitreal injection to the gerbil retina. Gerbil retinas were assessed 4 and 8 weeks later in vivo by in vivo bioluminescence (IVIS imaging system, PerkinElmer), which provides a quantitative readout of reporter expression across the entire eye.

As expected, expression of the luciferase reporter under the control of pMNTC was higher than expression of the luciferase reporter under the control of pR2.1. Replacement of the pMNTC promoter sequence with the pR2.1 promoter sequence having the most sequence homology to it (SEQ ID NO:83) reduced expression (construct pMNTC_pR2.1 L3′P), as did the inclusion of pR2.1 promoter sequence that lies more distal to the 5′UTR of pR2.1 (SEQ ID NO:82) (construct pMNTCpR2.1-L5′P). Expression was also reduced by the introduction into the pMNTC 5′UTR of two false start sequences (“AUG1” and “AUG2”) that were observed in the pR2.1 5′UTR (construct pMNTC_2.1-AUG1/2). Interestingly, expression was not reduced when the pMNTC 5′UTR was replaced with a modified pR2.1 5′UTR sequence in which these false starts had been removed (SEQ ID NO:87, nucleotide 17 changed to C, nt 61and 62 changed to CA) (pMNTC_pR2.1-5′UTR), suggesting that the pR2.1 5′UTR would promote strong expression in cone cells but for the false AUGs in the pR2.1 5′UTR element. Also interestingly, the pR2.1 intron (SEQ ID NO:59) appeared to provide more robust expression than the pSI chimeric intron of pMNTC, suggesting that inclusion of the pR2.1 intron in the polynucleotide cassettes of the present disclosure may be used to further improve expression in cone cells. Lastly, removal of the L/M enhancer (found in both pR2.1 and pMNTC) reduced expression as well. While the polyA tailed seemed at first to also have a significant impact on expression, re-sequencing of the pMNTC construct comprising this pR2.1 element revealed that the polyA tail was not operably linked to the transgene, thereby explaining why only background levels of expression were observed from this construct. Thus, the L/M opsin LCR, the inclusion of the M opsin core promoter rather than the L opsin promoter, and the exclusion of false starts in the 5′UTR all contribute to the enhancement in gene expression achieved using the pMNTC promoter.

In conclusion, we have identified an AAV variant, the AAV variant comprising a 7m8 peptide in the GH loop, which may be used for the intravitreal delivery of polynucleotides to retinal cones. Likewise, we have identified a number of polynucleotide cassette elements that may be used to promote strong expression in cone photoreceptors. Together, these discoveries represent improvements that may facilitate the development of therapeutic agents for cone-associated disorders.

Materials and Methods

Transgene expression in vitro in WERI-RB-1 cells. WERI-Rb-1 retinoblastoma cells expressing cone photoreceptor pigments cells are transfected with a polynucleotide cassette of the present disclosure according to the method described by Shaaban and Deeb, 1998; IOVS 39(6)885-896. The polynucleotide cassettes are transfected as plasmid DNA using well established techniques of molecular biology, such as cloning (Maniatis et al.) or via de novo DNA synthesis. All regulatory elements are placed in the cassette and used to drive the enhanced GFP protein. Plasmid DNA is then introduced into cells using established techniques for non-viral transfection, for example using a lipid-based transfection reagent (Altogen Biosystems, NV) or Lipofectamine LTX (Life Technologies). Cells are then cultured for 72 hours and eGFP expression is measured using flow cytometry and fluorescence microscopy. Transgene expression in cells transfected with the polynucleotide cassette of the present invention (i.e., constructs designed for cone photoreceptor expression) is compared to the un-optimized counterparts (i.e., those based on pR2.1) and is found to be stronger from cassettes carrying improved elements

In vitro expression is also evaluated using other mammalian cell lines that express cone opsins, such as 661W cells (Tan et al., IOVS 2004; 45(3) 764-768).

Similarly, in vitro expression is evaluated using non-photoreceptor cell lines that have been engineered to express cone photoreceptor-specific proteins. Such a system has been described with HEK293 cells that have been genetically engineered to express CRX/Spl (Khani et al., IOVS 2007; 48: 3954). Marker genes are also used (eGFP, dsRed, mCherry, luciferase) as well as physiologic genes (opsin, ACHR genes). Physiologic genes are tested by examining mRNA levels (e.g., by RT-PCR) or protein levels (e.g., by ELISA or Western blot).

Animal care. All experiments conformed to the principles regarding the care and use of animals adopted by the American Physiological Society and the Society for Neuroscience, and were approved by the Institutional Animal Care and Use Committee (IACUC).

Small animal studies. The expression of the gene product encoded by the coding sequence of the expression cassettes are evaluated in vivo in mice, rats, and gerbils. This is accomplished by intravitreal injection in vivo of an rAAV preparation comprising the expression cassette (Li et al., 2008; Mol Vis 48: 332-338). Note that electroporation of plasmid DNA may be performed instead (Matsuda/Cepko).

Mouse studies. Mice used in this study were C57BL/6. Animals were anesthetized with ketamine/xylazine (110 mg/kg intraperitoneal). A beveled 34 gauge disposable needle loaded with test article was inserted into the vitreous of the eye, and 5.04×10¹⁰ vector genomes of rAAV in a volume of 1.5 μl was injected into the vitreous.

Gerbil and rat studies. Mongolian gerbils (Meriones unguiculatus) and brown Norway rats were used in this study. Pupils were dilated with 10% phenylephrine and 0.5% tropicamide. Animals were anesthetized with an intraperitoneal or intramuscular injection of 0.1-0.2 mL of a ketamine/xylazine solution (70 mg/mL ketamine and 10 mg/mL xylazine for rats; 25 mg/mL ketamine and 0.3 mg/mL xylazine for gerbils). A beveled 34 gauge disposable needle loaded with test article in a 100 μL Hamilton syringe was inserted into the vitreous of the eye through the sclera at an optimized superior-temporal point about 1 mm from Limbus. 1×10¹⁰-2×10¹⁰ vector genomes of test article (2×10¹⁰ vg of rAAV.GFP, or 1.15×10¹⁰ vg of rAAV.luciferase) in a 5 uL volume was injected slowly with a microinjection pump into the vitreous, after which the needle tip was held in the injected eye at the injected position for 10 seconds so as to ensure adequate test article dispensing. The needle was then withdrawn.

Non-human primate (NHP) studies. The polynucleotide cassettes and expression vectors are also tested in large animals. This is done by using AAV, for example using the techniques of Mancuso et al. Briefly, an AAV cassette is made, the AAV encapsidating the expression cassette is manufactured, and the viral prep is injected intravitreally (up to 170 uL in the vitreous) or subretinally (up to 3, 100 uL injections at different locations; vitrectomy may be performed prior to injection) in nonhuman primates. Expression is evaluated by reporter (GFP), color ERG, and/or behavioral testing using the Cambridge Color Test or on animals trained to make a saccade (eye movement) when a target enters the field of view. The saccades are monitored using an eye tracker. Prior to treatment animals are trained to perform a color vision test or to make a saccade when it sees a colored target. An ERG is performed to estimate the spectral sensitivity of the cones present. Data from the color vision test performance and the ERG provide evidence that the animal is dichromatic (colorblind). For animals that receive a vector carrying the GFP gene, expression is monitored using fundus imaging with RetCam II or similar device under light that produces excitation of the GFP. For animals receiving a photopigment gene that differs in spectral sensitivity compared to the animal's endogenous pigments, expression is monitored using the multifocal color ERG to measure spectral sensitivity at up to 106 different retinal locations, and by behavioral testing.

Baboons were sedated with 10-15 mg/kg ketamine following by sevofluorane. African Green monkeys were sedated with an intramuscular injection of 5:1 ketamine:xylazine mix (0.2 ml/kg of 100 mg/ml ketamine and 20 mg/ml xylazine). Mydriasis was achieved with topical 10% phenylephrine. An eye speculum was placed in the eye to facilitate injections. A drop of proparacaine hydrochloride 0.5% and then 5% betadine solution was applied, followed by a rinse with sterile saline. Baboons (FIG. 6) received 60 μl of a 3.4×10¹³ vg preparation of rAAV by intravitreal (ITV) injection to yield a final dose of 2.02×10¹² vg per eye. African Green monkeys received 50 uL of a 1×10¹³ preparation of rAAV vector by ITV injection to yield a final dose of 5×10¹¹ vg per eye. ITV injections to the central vitreous were administered using a 31-gauge 0.375 inch needle (Terumo) inserted inferotemporally at the level of the ora serrata ˜2 5 mm poster to the limbus under a surgical magnification to allow full visualization of extraocular and intraocular needle placement. Central vitreous placement was confirmed by direct observation of the needle tip at the time of the injection. Following ITV injections a topical triple antibiotic ointment was administered.

Slit-lamp biomicroscopy. The anterior segment of each monkey eye was examined by slit-lamp biomicroscopy during baseline screening and at week 4 (day 28), week 8 (day 56) and week 12 (day 84) post-injection to monitor inflammation. No abnormalities were observed.

Fundus examination and photography. Eye examination and fundus photography of rat and gerbil retinas was performed using a Phoenix Micron IV fundus microscope. All animals received a baseline screening/photographing to confirm ocular health, and then photographed at the designated timepoints to monitor the expression of the GFP transgene. Any change to the optic nerves and retina or appearance of gross lesions were recorded by a color fundus photography and expression of GFP was visualized using fluorescence fundus imaging with a fluorescein filter.

Retinal examination, fundus color and fluorescence photography, and autofluorescence OCT of NHP were performed by using a Topcon TRC-50EX retinal camera with Canon 6D digital imaging hardware and New Vision Fundus Image Analysis System software and Spectralis OCT Plus. All animals received a baseline imaging. GFP expression was also documented at week 2, 4, 8, and 12 post-intravitreal vector injection.

IVIS Imaging System. Expression of luciferase in the retina following delivery of rAAV.luciferase was quantified in vivo 2, 4 and 8 weeks post-intravitreal injection using an IVIS Imaging System. Gerbils were injected subcutaneously with 150 mg/kg luciferin (PerkinElmer) (15 mg/ml luciferin at a dose of 15 ml/kg). Approximately 22 minutes later, animals were sedated by inhalation of 4% isoflurane for 3-5 minutes. Immediately thereafter, animals were placed on the imaging platform in pairs, and the luminescence of the one eye of each animal quantified followed immediately by imaging of the contralateral eye. A naïve gerbil was used as a negative standard, with background levels of luminescence typically registering a luminescence of 1×10⁴ photons/second. Bioluminescence verification using a phantom mouse (XPM-2 Perkin Elmer phantom mouse for bioluminescence imaging) was performed prior to imaging to ensure calibration of the imaging system.

Immunohistochemistry. Mice were euthanized with a lethal dose of sodium pentobarbital and tissues fixed via cardiac perfusion first with 0.13M phosphate buffered saline (PBS) pH 7.2-7.4 containing 2 units of heparin per mL, followed by 4% paraformaldehyde (PFA) in PBS, followed by 4% paraformaldehyde plus 1% glutaraldehyde in PBS. Glutaraldehyde served to keep the neural retina attached to the RPE so that the cone outer segments would remain intact. Each solution was warmed to ˜37° C. just prior to administration and ˜35-40 mL of perfusate was delivered at each stage. Once the perfusion was stopped, the mouse was wrapped in a moist paper towel and left to further fix for 2-3 hours before enucleation and dissection.

Permanent ink was used to mark the orientation of the eye, the anterior segment was removed, and the eye-cup was fixed in 4% PFA overnight at 4° C. and then stored in PBS at 4° C. Retinal whole-mounts were made by flattening the dissected retina between tissues soaked in 4% PFA for two hours and then transferring them to a culture plate for 6 more hours of fixation. Afterward, the PFA was replaced with PBS containing 0.03% sodium azide (Sigma).

Antibody labeling was carried out on a rotating table shaker. To block non-specific labeling, whole mounts were incubated overnight at 4° C. with a solution containing 5% donkey serum (Jackson ImmunoResearch, Cat #004-000-120), 1 mg/ml BSA (Jackson ImmunoResearch, Cat #001-000-161), and 0.03% Triton X-100 in PBS (pH 7.4). The primary antibody used in this study was rabbit anti red-green (L/M) opsin diluted 1:200 (Millipore, Cat #AB5405. Specimens were washed in PBS 3 times for 30 minutes each, then incubated at 4° C. overnight with DAPI (4′,6-diamidino-2-phenylindole, dihydrochloride 1:10,000; Invitrogen, Cat #D-21490) plus secondary antibodies. The secondary antibody for the L/M-opsin antibody was Alexa Fluor 488 labeled donkey anti-rabbit IgG(H+L) diluted 1:200 in antibody dilution buffer (Invitrogen, Cat # A21206). The incubation with secondary antibody was followed by three 30 minute PBS washes, 30 minutes of post-fixation with 4% paraformaldehyde, and three more 30 minute PBS washes. Finally, the retinal slices were placed on slides with 2% DABCO in glycerol and covered with cover slips.

Microscopy. Widefield images of mouse retina whole mounts were acquired using a Nikon Eclipse E1000 with a 20× (open-air) objective and camera set with a 1.5× optical zoom. For each specimen, 50 optical sections were taken 0.5 μm apart and the M-opsin Z-stack was reconstructed in ImageJ. The Z-stack was oriented so that the lengths of the outer segments were in plane, and the distance between where antibody staining began and ended was measured as an estimate of the length of the outer segments. Further, a 3D projection of the Z-stack was generated and the number of cones with visible M-opsin in the outer segment could be quantified.

Confocal image slices were acquired using an Olympus FluoView™ FV1000. Sections were imaged using a 20× oil immersion lens (40 images taken 0.5 μm apart) and the Z-stacks were reconstructed in ImageJ. Channel exposure levels were balanced within and across images using Adobe Photoshop. For the retinal whole mounts, images were taken using a 10× open-air lens and mosaics were constructed with Adobe Photoshop's native mosaic construction software.

Experiments testing the tissue specificity of the polynucleotide cassettes. In this instance, a construct encoding GFP is injected via one or more routes of administration, such as intravitreal, subretinal, or intravenously. The animal is then sacrificed and tissues are analyzed by qPCR—to detect DNA sequences indicating presence of the construct—and GFP expression—to detect areas where the construct is actively expressed. Whereas absence of DNA sequence indicates lack of biodistribution to a given tissue, the presence of DNA sequence together with the lack of transgene expression (mRNA or protein level) indicates presence of vector but lack of expression in that tissue. In this way, the level of specificity for cone photoreceptors can be established, and used to determine the utility of this invention in terms of restricting expression to target cone photoreceptor cells without expression in non-targeted tissues such as optic nerve, liver, spleen, or brain tissue. Intravitreal AAV is known to biodistribute to the brain (Provost et al) so highly expressed, improved constructs for targeting cone photoreceptors would be useful to limit expression to target cells of the retina and limit potential adverse events associated with off-target transgene expression.

The preceding merely illustrates the principles of the invention. It will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended to aid the reader in understanding the principles of the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of the present invention, therefore, is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of the present invention is embodied by the appended claims. 

What is claimed is:
 1. A polynucleotide cassette for enhanced expression of a transgene in cone cells of a mammalian retina, comprising (a) a promoter region consisting of a truncated M-Opsin promoter having a sequence identity of 85% or more to SEQ ID NO:80; (b) a coding sequence operatively linked to the promoter region; and (c) a polyadenylation site operatively linked to the coding sequence.
 2. The polynucleotide cassette of claim 1, further comprising a 5′ untranslated region (5′UTR) consisting essentially of a sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:84, SEQ ID NO:85, SEQ ID NO:86, SEQ ID NO:87, SEQ ID NO:88, and SEQ ID NO:89.
 3. The polynucleotide cassette of claim 2, wherein the 5′UTR does not comprise a polynucleotide ATG.
 4. The polynucleotide cassette of claim 2, wherein the 5′ UTR consists essentially of a sequence having a sequence identity of 85% or more to the full length of SEQ ID NO:85 or SEQ ID NO:86.
 5. The polynucleotide cassette of claim 2, further comprising an intron.
 6. The polynucleotide cassette of claim 5, wherein the intron comprises a sequence having a sequence identity of 85% or more to a sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:59, and SEQ ID NO:60.
 7. The polynucleotide cassette of claim 6, wherein the intron is located within the polynucleotide sequence comprising the 5′ UTR.
 8. The polynucleotide cassette of claim 1, further comprising a translation initiation sequence.
 9. The polynucleotide cassette of claim 8, wherein the translation initiation sequence comprises a polynucleotide sequence consisting essentially of SEQ ID NO:72 or SEQ ID NO:73.
 10. The polynucleotide cassette of claim 1, further comprising an enhancer sequence having a sequence identity of 85% or more to SEQ ID NO:52 or a functional fragment thereof.
 11. The polynucleotide cassette of claim 10, wherein the enhancer sequence consists essentially of a sequence having a sequence identity of 85% or more to the full length of SEQ ID NO:51.
 12. The polynucleotide cassette of claim 1, wherein expression of the coding sequence is greater than expression of the coding sequence when the promoter region is replaced with the promoter region of SEQ ID NO:1 when introduced into a mammalian cone cell.
 13. A recombinant adeno-associated virus (rAAV) comprising: a) an AAV capsid protein, and b) the polynucleotide cassette of claim 1 flanked by AAV ITRs.
 14. A pharmaceutical composition comprising the rAAV of claim 13 and a pharmaceutical excipient.
 15. A method for expressing a transgene in cone cells, comprising: contacting one or more cone cells with an effective amount of the recombinant adeno-associated virus of claim 13, wherein the transgene is expressed at detectable levels in the one or more cone cells.
 16. The method according to claim 15, comprising detecting the expression in the cone cells, wherein expression is detected in 60% or more of the cone cells.
 17. A method for the treatment or prophylaxis of a cone cell disorder in a mammal in need thereof, comprising administering to the eye of the mammal an effective amount of the pharmaceutical composition of claim 14, wherein the coding sequence encodes a therapeutic gene product, and the rAAV expresses the therapeutic gene product in the cone cells of the mammal.
 18. The method of claim 17, wherein the cone cell disorder is a macular dystrophy, a color vision disorder, or a vision disorder of the central macula.
 19. The method of claim 18, wherein the color vision disorder is selected from the group consisting of achromotopsia, blue cone monochromacy, a protan defect, a deutan defect, and a tritan defect.
 20. The method of claim 18, wherein the method further comprises detecting a change in the disease symptoms, wherein the change comprises an increase in the ability of the mammal to perceive a color.
 21. The method of claim 18, wherein the macular dystrophy is selected from the group consisting of Stargardt's macular dystrophy, cone dystrophy, cone-rod dystrophy, Spinocerebellar ataxia type 7, and Bardet-Biedl syndrome-1.
 22. The method of claim 18, wherein the vision disorder of the central macula is selected from the group consisting of age-related macular degeneration, macular telangiectasia, retinitis pigmentosa, diabetic retinopathy, retinal vein occlusions, glaucoma, Sorsby's fundus dystrophy, adult vitelliform macular dystrophy, Best's disease, rod-cone dystrophy, Leber's congenital amaurosis, and X-linked retinoschisis.
 23. The method of claim 18, wherein the method further comprises detecting a change in the disease symptoms, wherein the change comprises reducing the rate of visual acuity loss of the mammal.
 24. The polynucleotide cassette of claim 1, wherein the promoter region consists of SEQ ID NO:80.
 25. The polynucleotide cassette of claim 1, wherein the promoter region consists of a truncated M-Opsin promoter having a sequence identity of 95% or more to SEQ ID NO:80.
 26. A polynucleotide cassette for enhanced expression of a transgene in cone cells of a mammalian retina, comprising SEQ ID NO:95. 